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1 /*
2 Copyright (C) 2002 Richard Henderson
3 Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19 #include <linux/export.h>
20 #include <linux/moduleloader.h>
21 #include <linux/trace_events.h>
22 #include <linux/init.h>
23 #include <linux/kallsyms.h>
24 #include <linux/file.h>
25 #include <linux/fs.h>
26 #include <linux/sysfs.h>
27 #include <linux/kernel.h>
28 #include <linux/slab.h>
29 #include <linux/vmalloc.h>
30 #include <linux/elf.h>
31 #include <linux/proc_fs.h>
32 #include <linux/security.h>
33 #include <linux/seq_file.h>
34 #include <linux/syscalls.h>
35 #include <linux/fcntl.h>
36 #include <linux/rcupdate.h>
37 #include <linux/capability.h>
38 #include <linux/cpu.h>
39 #include <linux/moduleparam.h>
40 #include <linux/errno.h>
41 #include <linux/err.h>
42 #include <linux/vermagic.h>
43 #include <linux/notifier.h>
44 #include <linux/sched.h>
45 #include <linux/device.h>
46 #include <linux/string.h>
47 #include <linux/mutex.h>
48 #include <linux/rculist.h>
49 #include <asm/uaccess.h>
50 #include <asm/cacheflush.h>
51 #include <asm/mmu_context.h>
52 #include <linux/license.h>
53 #include <asm/sections.h>
54 #include <linux/tracepoint.h>
55 #include <linux/ftrace.h>
56 #include <linux/async.h>
57 #include <linux/percpu.h>
58 #include <linux/kmemleak.h>
59 #include <linux/jump_label.h>
60 #include <linux/pfn.h>
61 #include <linux/bsearch.h>
62 #include <uapi/linux/module.h>
63 #include "module-internal.h"
64
65 #define CREATE_TRACE_POINTS
66 #include <trace/events/module.h>
67
68 #ifndef ARCH_SHF_SMALL
69 #define ARCH_SHF_SMALL 0
70 #endif
71
72 /*
73 * Modules' sections will be aligned on page boundaries
74 * to ensure complete separation of code and data, but
75 * only when CONFIG_DEBUG_SET_MODULE_RONX=y
76 */
77 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
78 # define debug_align(X) ALIGN(X, PAGE_SIZE)
79 #else
80 # define debug_align(X) (X)
81 #endif
82
83 /*
84 * Given BASE and SIZE this macro calculates the number of pages the
85 * memory regions occupies
86 */
87 #define MOD_NUMBER_OF_PAGES(BASE, SIZE) (((SIZE) > 0) ? \
88 (PFN_DOWN((unsigned long)(BASE) + (SIZE) - 1) - \
89 PFN_DOWN((unsigned long)BASE) + 1) \
90 : (0UL))
91
92 /* If this is set, the section belongs in the init part of the module */
93 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
94
95 /*
96 * Mutex protects:
97 * 1) List of modules (also safely readable with preempt_disable),
98 * 2) module_use links,
99 * 3) module_addr_min/module_addr_max.
100 * (delete and add uses RCU list operations). */
101 DEFINE_MUTEX(module_mutex);
102 EXPORT_SYMBOL_GPL(module_mutex);
103 static LIST_HEAD(modules);
104
105 #ifdef CONFIG_MODULES_TREE_LOOKUP
106
107 /*
108 * Use a latched RB-tree for __module_address(); this allows us to use
109 * RCU-sched lookups of the address from any context.
110 *
111 * Because modules have two address ranges: init and core, we need two
112 * latch_tree_nodes entries. Therefore we need the back-pointer from
113 * mod_tree_node.
114 *
115 * Because init ranges are short lived we mark them unlikely and have placed
116 * them outside the critical cacheline in struct module.
117 *
118 * This is conditional on PERF_EVENTS || TRACING because those can really hit
119 * __module_address() hard by doing a lot of stack unwinding; potentially from
120 * NMI context.
121 */
122
123 static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
124 {
125 struct mod_tree_node *mtn = container_of(n, struct mod_tree_node, node);
126 struct module *mod = mtn->mod;
127
128 if (unlikely(mtn == &mod->mtn_init))
129 return (unsigned long)mod->module_init;
130
131 return (unsigned long)mod->module_core;
132 }
133
134 static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
135 {
136 struct mod_tree_node *mtn = container_of(n, struct mod_tree_node, node);
137 struct module *mod = mtn->mod;
138
139 if (unlikely(mtn == &mod->mtn_init))
140 return (unsigned long)mod->init_size;
141
142 return (unsigned long)mod->core_size;
143 }
144
145 static __always_inline bool
146 mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
147 {
148 return __mod_tree_val(a) < __mod_tree_val(b);
149 }
150
151 static __always_inline int
152 mod_tree_comp(void *key, struct latch_tree_node *n)
153 {
154 unsigned long val = (unsigned long)key;
155 unsigned long start, end;
156
157 start = __mod_tree_val(n);
158 if (val < start)
159 return -1;
160
161 end = start + __mod_tree_size(n);
162 if (val >= end)
163 return 1;
164
165 return 0;
166 }
167
168 static const struct latch_tree_ops mod_tree_ops = {
169 .less = mod_tree_less,
170 .comp = mod_tree_comp,
171 };
172
173 static struct mod_tree_root {
174 struct latch_tree_root root;
175 unsigned long addr_min;
176 unsigned long addr_max;
177 } mod_tree __cacheline_aligned = {
178 .addr_min = -1UL,
179 };
180
181 #define module_addr_min mod_tree.addr_min
182 #define module_addr_max mod_tree.addr_max
183
184 static noinline void __mod_tree_insert(struct mod_tree_node *node)
185 {
186 latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
187 }
188
189 static void __mod_tree_remove(struct mod_tree_node *node)
190 {
191 latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
192 }
193
194 /*
195 * These modifications: insert, remove_init and remove; are serialized by the
196 * module_mutex.
197 */
198 static void mod_tree_insert(struct module *mod)
199 {
200 mod->mtn_core.mod = mod;
201 mod->mtn_init.mod = mod;
202
203 __mod_tree_insert(&mod->mtn_core);
204 if (mod->init_size)
205 __mod_tree_insert(&mod->mtn_init);
206 }
207
208 static void mod_tree_remove_init(struct module *mod)
209 {
210 if (mod->init_size)
211 __mod_tree_remove(&mod->mtn_init);
212 }
213
214 static void mod_tree_remove(struct module *mod)
215 {
216 __mod_tree_remove(&mod->mtn_core);
217 mod_tree_remove_init(mod);
218 }
219
220 static struct module *mod_find(unsigned long addr)
221 {
222 struct latch_tree_node *ltn;
223
224 ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
225 if (!ltn)
226 return NULL;
227
228 return container_of(ltn, struct mod_tree_node, node)->mod;
229 }
230
231 #else /* MODULES_TREE_LOOKUP */
232
233 static unsigned long module_addr_min = -1UL, module_addr_max = 0;
234
235 static void mod_tree_insert(struct module *mod) { }
236 static void mod_tree_remove_init(struct module *mod) { }
237 static void mod_tree_remove(struct module *mod) { }
238
239 static struct module *mod_find(unsigned long addr)
240 {
241 struct module *mod;
242
243 list_for_each_entry_rcu(mod, &modules, list) {
244 if (within_module(addr, mod))
245 return mod;
246 }
247
248 return NULL;
249 }
250
251 #endif /* MODULES_TREE_LOOKUP */
252
253 /*
254 * Bounds of module text, for speeding up __module_address.
255 * Protected by module_mutex.
256 */
257 static void __mod_update_bounds(void *base, unsigned int size)
258 {
259 unsigned long min = (unsigned long)base;
260 unsigned long max = min + size;
261
262 if (min < module_addr_min)
263 module_addr_min = min;
264 if (max > module_addr_max)
265 module_addr_max = max;
266 }
267
268 static void mod_update_bounds(struct module *mod)
269 {
270 __mod_update_bounds(mod->module_core, mod->core_size);
271 if (mod->init_size)
272 __mod_update_bounds(mod->module_init, mod->init_size);
273 }
274
275 #ifdef CONFIG_KGDB_KDB
276 struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
277 #endif /* CONFIG_KGDB_KDB */
278
279 static void module_assert_mutex(void)
280 {
281 lockdep_assert_held(&module_mutex);
282 }
283
284 static void module_assert_mutex_or_preempt(void)
285 {
286 #ifdef CONFIG_LOCKDEP
287 if (unlikely(!debug_locks))
288 return;
289
290 WARN_ON(!rcu_read_lock_sched_held() &&
291 !lockdep_is_held(&module_mutex));
292 #endif
293 }
294
295 static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
296 #ifndef CONFIG_MODULE_SIG_FORCE
297 module_param(sig_enforce, bool_enable_only, 0644);
298 #endif /* !CONFIG_MODULE_SIG_FORCE */
299
300 /* Block module loading/unloading? */
301 int modules_disabled = 0;
302 core_param(nomodule, modules_disabled, bint, 0);
303
304 /* Waiting for a module to finish initializing? */
305 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
306
307 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
308
309 int register_module_notifier(struct notifier_block *nb)
310 {
311 return blocking_notifier_chain_register(&module_notify_list, nb);
312 }
313 EXPORT_SYMBOL(register_module_notifier);
314
315 int unregister_module_notifier(struct notifier_block *nb)
316 {
317 return blocking_notifier_chain_unregister(&module_notify_list, nb);
318 }
319 EXPORT_SYMBOL(unregister_module_notifier);
320
321 struct load_info {
322 Elf_Ehdr *hdr;
323 unsigned long len;
324 Elf_Shdr *sechdrs;
325 char *secstrings, *strtab;
326 unsigned long symoffs, stroffs;
327 struct _ddebug *debug;
328 unsigned int num_debug;
329 bool sig_ok;
330 struct {
331 unsigned int sym, str, mod, vers, info, pcpu;
332 } index;
333 };
334
335 /* We require a truly strong try_module_get(): 0 means failure due to
336 ongoing or failed initialization etc. */
337 static inline int strong_try_module_get(struct module *mod)
338 {
339 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
340 if (mod && mod->state == MODULE_STATE_COMING)
341 return -EBUSY;
342 if (try_module_get(mod))
343 return 0;
344 else
345 return -ENOENT;
346 }
347
348 static inline void add_taint_module(struct module *mod, unsigned flag,
349 enum lockdep_ok lockdep_ok)
350 {
351 add_taint(flag, lockdep_ok);
352 mod->taints |= (1U << flag);
353 }
354
355 /*
356 * A thread that wants to hold a reference to a module only while it
357 * is running can call this to safely exit. nfsd and lockd use this.
358 */
359 void __module_put_and_exit(struct module *mod, long code)
360 {
361 module_put(mod);
362 do_exit(code);
363 }
364 EXPORT_SYMBOL(__module_put_and_exit);
365
366 /* Find a module section: 0 means not found. */
367 static unsigned int find_sec(const struct load_info *info, const char *name)
368 {
369 unsigned int i;
370
371 for (i = 1; i < info->hdr->e_shnum; i++) {
372 Elf_Shdr *shdr = &info->sechdrs[i];
373 /* Alloc bit cleared means "ignore it." */
374 if ((shdr->sh_flags & SHF_ALLOC)
375 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
376 return i;
377 }
378 return 0;
379 }
380
381 /* Find a module section, or NULL. */
382 static void *section_addr(const struct load_info *info, const char *name)
383 {
384 /* Section 0 has sh_addr 0. */
385 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
386 }
387
388 /* Find a module section, or NULL. Fill in number of "objects" in section. */
389 static void *section_objs(const struct load_info *info,
390 const char *name,
391 size_t object_size,
392 unsigned int *num)
393 {
394 unsigned int sec = find_sec(info, name);
395
396 /* Section 0 has sh_addr 0 and sh_size 0. */
397 *num = info->sechdrs[sec].sh_size / object_size;
398 return (void *)info->sechdrs[sec].sh_addr;
399 }
400
401 /* Provided by the linker */
402 extern const struct kernel_symbol __start___ksymtab[];
403 extern const struct kernel_symbol __stop___ksymtab[];
404 extern const struct kernel_symbol __start___ksymtab_gpl[];
405 extern const struct kernel_symbol __stop___ksymtab_gpl[];
406 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
407 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
408 extern const unsigned long __start___kcrctab[];
409 extern const unsigned long __start___kcrctab_gpl[];
410 extern const unsigned long __start___kcrctab_gpl_future[];
411 #ifdef CONFIG_UNUSED_SYMBOLS
412 extern const struct kernel_symbol __start___ksymtab_unused[];
413 extern const struct kernel_symbol __stop___ksymtab_unused[];
414 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
415 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
416 extern const unsigned long __start___kcrctab_unused[];
417 extern const unsigned long __start___kcrctab_unused_gpl[];
418 #endif
419
420 #ifndef CONFIG_MODVERSIONS
421 #define symversion(base, idx) NULL
422 #else
423 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
424 #endif
425
426 static bool each_symbol_in_section(const struct symsearch *arr,
427 unsigned int arrsize,
428 struct module *owner,
429 bool (*fn)(const struct symsearch *syms,
430 struct module *owner,
431 void *data),
432 void *data)
433 {
434 unsigned int j;
435
436 for (j = 0; j < arrsize; j++) {
437 if (fn(&arr[j], owner, data))
438 return true;
439 }
440
441 return false;
442 }
443
444 /* Returns true as soon as fn returns true, otherwise false. */
445 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
446 struct module *owner,
447 void *data),
448 void *data)
449 {
450 struct module *mod;
451 static const struct symsearch arr[] = {
452 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
453 NOT_GPL_ONLY, false },
454 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
455 __start___kcrctab_gpl,
456 GPL_ONLY, false },
457 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
458 __start___kcrctab_gpl_future,
459 WILL_BE_GPL_ONLY, false },
460 #ifdef CONFIG_UNUSED_SYMBOLS
461 { __start___ksymtab_unused, __stop___ksymtab_unused,
462 __start___kcrctab_unused,
463 NOT_GPL_ONLY, true },
464 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
465 __start___kcrctab_unused_gpl,
466 GPL_ONLY, true },
467 #endif
468 };
469
470 module_assert_mutex_or_preempt();
471
472 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
473 return true;
474
475 list_for_each_entry_rcu(mod, &modules, list) {
476 struct symsearch arr[] = {
477 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
478 NOT_GPL_ONLY, false },
479 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
480 mod->gpl_crcs,
481 GPL_ONLY, false },
482 { mod->gpl_future_syms,
483 mod->gpl_future_syms + mod->num_gpl_future_syms,
484 mod->gpl_future_crcs,
485 WILL_BE_GPL_ONLY, false },
486 #ifdef CONFIG_UNUSED_SYMBOLS
487 { mod->unused_syms,
488 mod->unused_syms + mod->num_unused_syms,
489 mod->unused_crcs,
490 NOT_GPL_ONLY, true },
491 { mod->unused_gpl_syms,
492 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
493 mod->unused_gpl_crcs,
494 GPL_ONLY, true },
495 #endif
496 };
497
498 if (mod->state == MODULE_STATE_UNFORMED)
499 continue;
500
501 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
502 return true;
503 }
504 return false;
505 }
506 EXPORT_SYMBOL_GPL(each_symbol_section);
507
508 struct find_symbol_arg {
509 /* Input */
510 const char *name;
511 bool gplok;
512 bool warn;
513
514 /* Output */
515 struct module *owner;
516 const unsigned long *crc;
517 const struct kernel_symbol *sym;
518 };
519
520 static bool check_symbol(const struct symsearch *syms,
521 struct module *owner,
522 unsigned int symnum, void *data)
523 {
524 struct find_symbol_arg *fsa = data;
525
526 if (!fsa->gplok) {
527 if (syms->licence == GPL_ONLY)
528 return false;
529 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
530 pr_warn("Symbol %s is being used by a non-GPL module, "
531 "which will not be allowed in the future\n",
532 fsa->name);
533 }
534 }
535
536 #ifdef CONFIG_UNUSED_SYMBOLS
537 if (syms->unused && fsa->warn) {
538 pr_warn("Symbol %s is marked as UNUSED, however this module is "
539 "using it.\n", fsa->name);
540 pr_warn("This symbol will go away in the future.\n");
541 pr_warn("Please evaluate if this is the right api to use and "
542 "if it really is, submit a report to the linux kernel "
543 "mailing list together with submitting your code for "
544 "inclusion.\n");
545 }
546 #endif
547
548 fsa->owner = owner;
549 fsa->crc = symversion(syms->crcs, symnum);
550 fsa->sym = &syms->start[symnum];
551 return true;
552 }
553
554 static int cmp_name(const void *va, const void *vb)
555 {
556 const char *a;
557 const struct kernel_symbol *b;
558 a = va; b = vb;
559 return strcmp(a, b->name);
560 }
561
562 static bool find_symbol_in_section(const struct symsearch *syms,
563 struct module *owner,
564 void *data)
565 {
566 struct find_symbol_arg *fsa = data;
567 struct kernel_symbol *sym;
568
569 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
570 sizeof(struct kernel_symbol), cmp_name);
571
572 if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
573 return true;
574
575 return false;
576 }
577
578 /* Find a symbol and return it, along with, (optional) crc and
579 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
580 const struct kernel_symbol *find_symbol(const char *name,
581 struct module **owner,
582 const unsigned long **crc,
583 bool gplok,
584 bool warn)
585 {
586 struct find_symbol_arg fsa;
587
588 fsa.name = name;
589 fsa.gplok = gplok;
590 fsa.warn = warn;
591
592 if (each_symbol_section(find_symbol_in_section, &fsa)) {
593 if (owner)
594 *owner = fsa.owner;
595 if (crc)
596 *crc = fsa.crc;
597 return fsa.sym;
598 }
599
600 pr_debug("Failed to find symbol %s\n", name);
601 return NULL;
602 }
603 EXPORT_SYMBOL_GPL(find_symbol);
604
605 /*
606 * Search for module by name: must hold module_mutex (or preempt disabled
607 * for read-only access).
608 */
609 static struct module *find_module_all(const char *name, size_t len,
610 bool even_unformed)
611 {
612 struct module *mod;
613
614 module_assert_mutex_or_preempt();
615
616 list_for_each_entry(mod, &modules, list) {
617 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
618 continue;
619 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
620 return mod;
621 }
622 return NULL;
623 }
624
625 struct module *find_module(const char *name)
626 {
627 module_assert_mutex();
628 return find_module_all(name, strlen(name), false);
629 }
630 EXPORT_SYMBOL_GPL(find_module);
631
632 #ifdef CONFIG_SMP
633
634 static inline void __percpu *mod_percpu(struct module *mod)
635 {
636 return mod->percpu;
637 }
638
639 static int percpu_modalloc(struct module *mod, struct load_info *info)
640 {
641 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
642 unsigned long align = pcpusec->sh_addralign;
643
644 if (!pcpusec->sh_size)
645 return 0;
646
647 if (align > PAGE_SIZE) {
648 pr_warn("%s: per-cpu alignment %li > %li\n",
649 mod->name, align, PAGE_SIZE);
650 align = PAGE_SIZE;
651 }
652
653 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
654 if (!mod->percpu) {
655 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
656 mod->name, (unsigned long)pcpusec->sh_size);
657 return -ENOMEM;
658 }
659 mod->percpu_size = pcpusec->sh_size;
660 return 0;
661 }
662
663 static void percpu_modfree(struct module *mod)
664 {
665 free_percpu(mod->percpu);
666 }
667
668 static unsigned int find_pcpusec(struct load_info *info)
669 {
670 return find_sec(info, ".data..percpu");
671 }
672
673 static void percpu_modcopy(struct module *mod,
674 const void *from, unsigned long size)
675 {
676 int cpu;
677
678 for_each_possible_cpu(cpu)
679 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
680 }
681
682 /**
683 * is_module_percpu_address - test whether address is from module static percpu
684 * @addr: address to test
685 *
686 * Test whether @addr belongs to module static percpu area.
687 *
688 * RETURNS:
689 * %true if @addr is from module static percpu area
690 */
691 bool is_module_percpu_address(unsigned long addr)
692 {
693 struct module *mod;
694 unsigned int cpu;
695
696 preempt_disable();
697
698 list_for_each_entry_rcu(mod, &modules, list) {
699 if (mod->state == MODULE_STATE_UNFORMED)
700 continue;
701 if (!mod->percpu_size)
702 continue;
703 for_each_possible_cpu(cpu) {
704 void *start = per_cpu_ptr(mod->percpu, cpu);
705
706 if ((void *)addr >= start &&
707 (void *)addr < start + mod->percpu_size) {
708 preempt_enable();
709 return true;
710 }
711 }
712 }
713
714 preempt_enable();
715 return false;
716 }
717
718 #else /* ... !CONFIG_SMP */
719
720 static inline void __percpu *mod_percpu(struct module *mod)
721 {
722 return NULL;
723 }
724 static int percpu_modalloc(struct module *mod, struct load_info *info)
725 {
726 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
727 if (info->sechdrs[info->index.pcpu].sh_size != 0)
728 return -ENOMEM;
729 return 0;
730 }
731 static inline void percpu_modfree(struct module *mod)
732 {
733 }
734 static unsigned int find_pcpusec(struct load_info *info)
735 {
736 return 0;
737 }
738 static inline void percpu_modcopy(struct module *mod,
739 const void *from, unsigned long size)
740 {
741 /* pcpusec should be 0, and size of that section should be 0. */
742 BUG_ON(size != 0);
743 }
744 bool is_module_percpu_address(unsigned long addr)
745 {
746 return false;
747 }
748
749 #endif /* CONFIG_SMP */
750
751 #define MODINFO_ATTR(field) \
752 static void setup_modinfo_##field(struct module *mod, const char *s) \
753 { \
754 mod->field = kstrdup(s, GFP_KERNEL); \
755 } \
756 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
757 struct module_kobject *mk, char *buffer) \
758 { \
759 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
760 } \
761 static int modinfo_##field##_exists(struct module *mod) \
762 { \
763 return mod->field != NULL; \
764 } \
765 static void free_modinfo_##field(struct module *mod) \
766 { \
767 kfree(mod->field); \
768 mod->field = NULL; \
769 } \
770 static struct module_attribute modinfo_##field = { \
771 .attr = { .name = __stringify(field), .mode = 0444 }, \
772 .show = show_modinfo_##field, \
773 .setup = setup_modinfo_##field, \
774 .test = modinfo_##field##_exists, \
775 .free = free_modinfo_##field, \
776 };
777
778 MODINFO_ATTR(version);
779 MODINFO_ATTR(srcversion);
780
781 static char last_unloaded_module[MODULE_NAME_LEN+1];
782
783 #ifdef CONFIG_MODULE_UNLOAD
784
785 EXPORT_TRACEPOINT_SYMBOL(module_get);
786
787 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
788 #define MODULE_REF_BASE 1
789
790 /* Init the unload section of the module. */
791 static int module_unload_init(struct module *mod)
792 {
793 /*
794 * Initialize reference counter to MODULE_REF_BASE.
795 * refcnt == 0 means module is going.
796 */
797 atomic_set(&mod->refcnt, MODULE_REF_BASE);
798
799 INIT_LIST_HEAD(&mod->source_list);
800 INIT_LIST_HEAD(&mod->target_list);
801
802 /* Hold reference count during initialization. */
803 atomic_inc(&mod->refcnt);
804
805 return 0;
806 }
807
808 /* Does a already use b? */
809 static int already_uses(struct module *a, struct module *b)
810 {
811 struct module_use *use;
812
813 list_for_each_entry(use, &b->source_list, source_list) {
814 if (use->source == a) {
815 pr_debug("%s uses %s!\n", a->name, b->name);
816 return 1;
817 }
818 }
819 pr_debug("%s does not use %s!\n", a->name, b->name);
820 return 0;
821 }
822
823 /*
824 * Module a uses b
825 * - we add 'a' as a "source", 'b' as a "target" of module use
826 * - the module_use is added to the list of 'b' sources (so
827 * 'b' can walk the list to see who sourced them), and of 'a'
828 * targets (so 'a' can see what modules it targets).
829 */
830 static int add_module_usage(struct module *a, struct module *b)
831 {
832 struct module_use *use;
833
834 pr_debug("Allocating new usage for %s.\n", a->name);
835 use = kmalloc(sizeof(*use), GFP_ATOMIC);
836 if (!use) {
837 pr_warn("%s: out of memory loading\n", a->name);
838 return -ENOMEM;
839 }
840
841 use->source = a;
842 use->target = b;
843 list_add(&use->source_list, &b->source_list);
844 list_add(&use->target_list, &a->target_list);
845 return 0;
846 }
847
848 /* Module a uses b: caller needs module_mutex() */
849 int ref_module(struct module *a, struct module *b)
850 {
851 int err;
852
853 if (b == NULL || already_uses(a, b))
854 return 0;
855
856 /* If module isn't available, we fail. */
857 err = strong_try_module_get(b);
858 if (err)
859 return err;
860
861 err = add_module_usage(a, b);
862 if (err) {
863 module_put(b);
864 return err;
865 }
866 return 0;
867 }
868 EXPORT_SYMBOL_GPL(ref_module);
869
870 /* Clear the unload stuff of the module. */
871 static void module_unload_free(struct module *mod)
872 {
873 struct module_use *use, *tmp;
874
875 mutex_lock(&module_mutex);
876 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
877 struct module *i = use->target;
878 pr_debug("%s unusing %s\n", mod->name, i->name);
879 module_put(i);
880 list_del(&use->source_list);
881 list_del(&use->target_list);
882 kfree(use);
883 }
884 mutex_unlock(&module_mutex);
885 }
886
887 #ifdef CONFIG_MODULE_FORCE_UNLOAD
888 static inline int try_force_unload(unsigned int flags)
889 {
890 int ret = (flags & O_TRUNC);
891 if (ret)
892 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
893 return ret;
894 }
895 #else
896 static inline int try_force_unload(unsigned int flags)
897 {
898 return 0;
899 }
900 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
901
902 /* Try to release refcount of module, 0 means success. */
903 static int try_release_module_ref(struct module *mod)
904 {
905 int ret;
906
907 /* Try to decrement refcnt which we set at loading */
908 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
909 BUG_ON(ret < 0);
910 if (ret)
911 /* Someone can put this right now, recover with checking */
912 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
913
914 return ret;
915 }
916
917 static int try_stop_module(struct module *mod, int flags, int *forced)
918 {
919 /* If it's not unused, quit unless we're forcing. */
920 if (try_release_module_ref(mod) != 0) {
921 *forced = try_force_unload(flags);
922 if (!(*forced))
923 return -EWOULDBLOCK;
924 }
925
926 /* Mark it as dying. */
927 mod->state = MODULE_STATE_GOING;
928
929 return 0;
930 }
931
932 /**
933 * module_refcount - return the refcount or -1 if unloading
934 *
935 * @mod: the module we're checking
936 *
937 * Returns:
938 * -1 if the module is in the process of unloading
939 * otherwise the number of references in the kernel to the module
940 */
941 int module_refcount(struct module *mod)
942 {
943 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
944 }
945 EXPORT_SYMBOL(module_refcount);
946
947 /* This exists whether we can unload or not */
948 static void free_module(struct module *mod);
949
950 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
951 unsigned int, flags)
952 {
953 struct module *mod;
954 char name[MODULE_NAME_LEN];
955 int ret, forced = 0;
956
957 if (!capable(CAP_SYS_MODULE) || modules_disabled)
958 return -EPERM;
959
960 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
961 return -EFAULT;
962 name[MODULE_NAME_LEN-1] = '\0';
963
964 if (mutex_lock_interruptible(&module_mutex) != 0)
965 return -EINTR;
966
967 mod = find_module(name);
968 if (!mod) {
969 ret = -ENOENT;
970 goto out;
971 }
972
973 if (!list_empty(&mod->source_list)) {
974 /* Other modules depend on us: get rid of them first. */
975 ret = -EWOULDBLOCK;
976 goto out;
977 }
978
979 /* Doing init or already dying? */
980 if (mod->state != MODULE_STATE_LIVE) {
981 /* FIXME: if (force), slam module count damn the torpedoes */
982 pr_debug("%s already dying\n", mod->name);
983 ret = -EBUSY;
984 goto out;
985 }
986
987 /* If it has an init func, it must have an exit func to unload */
988 if (mod->init && !mod->exit) {
989 forced = try_force_unload(flags);
990 if (!forced) {
991 /* This module can't be removed */
992 ret = -EBUSY;
993 goto out;
994 }
995 }
996
997 /* Stop the machine so refcounts can't move and disable module. */
998 ret = try_stop_module(mod, flags, &forced);
999 if (ret != 0)
1000 goto out;
1001
1002 mutex_unlock(&module_mutex);
1003 /* Final destruction now no one is using it. */
1004 if (mod->exit != NULL)
1005 mod->exit();
1006 blocking_notifier_call_chain(&module_notify_list,
1007 MODULE_STATE_GOING, mod);
1008 async_synchronize_full();
1009
1010 /* Store the name of the last unloaded module for diagnostic purposes */
1011 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
1012
1013 free_module(mod);
1014 return 0;
1015 out:
1016 mutex_unlock(&module_mutex);
1017 return ret;
1018 }
1019
1020 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1021 {
1022 struct module_use *use;
1023 int printed_something = 0;
1024
1025 seq_printf(m, " %i ", module_refcount(mod));
1026
1027 /*
1028 * Always include a trailing , so userspace can differentiate
1029 * between this and the old multi-field proc format.
1030 */
1031 list_for_each_entry(use, &mod->source_list, source_list) {
1032 printed_something = 1;
1033 seq_printf(m, "%s,", use->source->name);
1034 }
1035
1036 if (mod->init != NULL && mod->exit == NULL) {
1037 printed_something = 1;
1038 seq_puts(m, "[permanent],");
1039 }
1040
1041 if (!printed_something)
1042 seq_puts(m, "-");
1043 }
1044
1045 void __symbol_put(const char *symbol)
1046 {
1047 struct module *owner;
1048
1049 preempt_disable();
1050 if (!find_symbol(symbol, &owner, NULL, true, false))
1051 BUG();
1052 module_put(owner);
1053 preempt_enable();
1054 }
1055 EXPORT_SYMBOL(__symbol_put);
1056
1057 /* Note this assumes addr is a function, which it currently always is. */
1058 void symbol_put_addr(void *addr)
1059 {
1060 struct module *modaddr;
1061 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1062
1063 if (core_kernel_text(a))
1064 return;
1065
1066 /*
1067 * Even though we hold a reference on the module; we still need to
1068 * disable preemption in order to safely traverse the data structure.
1069 */
1070 preempt_disable();
1071 modaddr = __module_text_address(a);
1072 BUG_ON(!modaddr);
1073 module_put(modaddr);
1074 preempt_enable();
1075 }
1076 EXPORT_SYMBOL_GPL(symbol_put_addr);
1077
1078 static ssize_t show_refcnt(struct module_attribute *mattr,
1079 struct module_kobject *mk, char *buffer)
1080 {
1081 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1082 }
1083
1084 static struct module_attribute modinfo_refcnt =
1085 __ATTR(refcnt, 0444, show_refcnt, NULL);
1086
1087 void __module_get(struct module *module)
1088 {
1089 if (module) {
1090 preempt_disable();
1091 atomic_inc(&module->refcnt);
1092 trace_module_get(module, _RET_IP_);
1093 preempt_enable();
1094 }
1095 }
1096 EXPORT_SYMBOL(__module_get);
1097
1098 bool try_module_get(struct module *module)
1099 {
1100 bool ret = true;
1101
1102 if (module) {
1103 preempt_disable();
1104 /* Note: here, we can fail to get a reference */
1105 if (likely(module_is_live(module) &&
1106 atomic_inc_not_zero(&module->refcnt) != 0))
1107 trace_module_get(module, _RET_IP_);
1108 else
1109 ret = false;
1110
1111 preempt_enable();
1112 }
1113 return ret;
1114 }
1115 EXPORT_SYMBOL(try_module_get);
1116
1117 void module_put(struct module *module)
1118 {
1119 int ret;
1120
1121 if (module) {
1122 preempt_disable();
1123 ret = atomic_dec_if_positive(&module->refcnt);
1124 WARN_ON(ret < 0); /* Failed to put refcount */
1125 trace_module_put(module, _RET_IP_);
1126 preempt_enable();
1127 }
1128 }
1129 EXPORT_SYMBOL(module_put);
1130
1131 #else /* !CONFIG_MODULE_UNLOAD */
1132 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1133 {
1134 /* We don't know the usage count, or what modules are using. */
1135 seq_puts(m, " - -");
1136 }
1137
1138 static inline void module_unload_free(struct module *mod)
1139 {
1140 }
1141
1142 int ref_module(struct module *a, struct module *b)
1143 {
1144 return strong_try_module_get(b);
1145 }
1146 EXPORT_SYMBOL_GPL(ref_module);
1147
1148 static inline int module_unload_init(struct module *mod)
1149 {
1150 return 0;
1151 }
1152 #endif /* CONFIG_MODULE_UNLOAD */
1153
1154 static size_t module_flags_taint(struct module *mod, char *buf)
1155 {
1156 size_t l = 0;
1157
1158 if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
1159 buf[l++] = 'P';
1160 if (mod->taints & (1 << TAINT_OOT_MODULE))
1161 buf[l++] = 'O';
1162 if (mod->taints & (1 << TAINT_FORCED_MODULE))
1163 buf[l++] = 'F';
1164 if (mod->taints & (1 << TAINT_CRAP))
1165 buf[l++] = 'C';
1166 if (mod->taints & (1 << TAINT_UNSIGNED_MODULE))
1167 buf[l++] = 'E';
1168 /*
1169 * TAINT_FORCED_RMMOD: could be added.
1170 * TAINT_CPU_OUT_OF_SPEC, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
1171 * apply to modules.
1172 */
1173 return l;
1174 }
1175
1176 static ssize_t show_initstate(struct module_attribute *mattr,
1177 struct module_kobject *mk, char *buffer)
1178 {
1179 const char *state = "unknown";
1180
1181 switch (mk->mod->state) {
1182 case MODULE_STATE_LIVE:
1183 state = "live";
1184 break;
1185 case MODULE_STATE_COMING:
1186 state = "coming";
1187 break;
1188 case MODULE_STATE_GOING:
1189 state = "going";
1190 break;
1191 default:
1192 BUG();
1193 }
1194 return sprintf(buffer, "%s\n", state);
1195 }
1196
1197 static struct module_attribute modinfo_initstate =
1198 __ATTR(initstate, 0444, show_initstate, NULL);
1199
1200 static ssize_t store_uevent(struct module_attribute *mattr,
1201 struct module_kobject *mk,
1202 const char *buffer, size_t count)
1203 {
1204 enum kobject_action action;
1205
1206 if (kobject_action_type(buffer, count, &action) == 0)
1207 kobject_uevent(&mk->kobj, action);
1208 return count;
1209 }
1210
1211 struct module_attribute module_uevent =
1212 __ATTR(uevent, 0200, NULL, store_uevent);
1213
1214 static ssize_t show_coresize(struct module_attribute *mattr,
1215 struct module_kobject *mk, char *buffer)
1216 {
1217 return sprintf(buffer, "%u\n", mk->mod->core_size);
1218 }
1219
1220 static struct module_attribute modinfo_coresize =
1221 __ATTR(coresize, 0444, show_coresize, NULL);
1222
1223 static ssize_t show_initsize(struct module_attribute *mattr,
1224 struct module_kobject *mk, char *buffer)
1225 {
1226 return sprintf(buffer, "%u\n", mk->mod->init_size);
1227 }
1228
1229 static struct module_attribute modinfo_initsize =
1230 __ATTR(initsize, 0444, show_initsize, NULL);
1231
1232 static ssize_t show_taint(struct module_attribute *mattr,
1233 struct module_kobject *mk, char *buffer)
1234 {
1235 size_t l;
1236
1237 l = module_flags_taint(mk->mod, buffer);
1238 buffer[l++] = '\n';
1239 return l;
1240 }
1241
1242 static struct module_attribute modinfo_taint =
1243 __ATTR(taint, 0444, show_taint, NULL);
1244
1245 static struct module_attribute *modinfo_attrs[] = {
1246 &module_uevent,
1247 &modinfo_version,
1248 &modinfo_srcversion,
1249 &modinfo_initstate,
1250 &modinfo_coresize,
1251 &modinfo_initsize,
1252 &modinfo_taint,
1253 #ifdef CONFIG_MODULE_UNLOAD
1254 &modinfo_refcnt,
1255 #endif
1256 NULL,
1257 };
1258
1259 static const char vermagic[] = VERMAGIC_STRING;
1260
1261 static int try_to_force_load(struct module *mod, const char *reason)
1262 {
1263 #ifdef CONFIG_MODULE_FORCE_LOAD
1264 if (!test_taint(TAINT_FORCED_MODULE))
1265 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1266 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1267 return 0;
1268 #else
1269 return -ENOEXEC;
1270 #endif
1271 }
1272
1273 #ifdef CONFIG_MODVERSIONS
1274 /* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
1275 static unsigned long maybe_relocated(unsigned long crc,
1276 const struct module *crc_owner)
1277 {
1278 #ifdef ARCH_RELOCATES_KCRCTAB
1279 if (crc_owner == NULL)
1280 return crc - (unsigned long)reloc_start;
1281 #endif
1282 return crc;
1283 }
1284
1285 static int check_version(Elf_Shdr *sechdrs,
1286 unsigned int versindex,
1287 const char *symname,
1288 struct module *mod,
1289 const unsigned long *crc,
1290 const struct module *crc_owner)
1291 {
1292 unsigned int i, num_versions;
1293 struct modversion_info *versions;
1294
1295 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1296 if (!crc)
1297 return 1;
1298
1299 /* No versions at all? modprobe --force does this. */
1300 if (versindex == 0)
1301 return try_to_force_load(mod, symname) == 0;
1302
1303 versions = (void *) sechdrs[versindex].sh_addr;
1304 num_versions = sechdrs[versindex].sh_size
1305 / sizeof(struct modversion_info);
1306
1307 for (i = 0; i < num_versions; i++) {
1308 if (strcmp(versions[i].name, symname) != 0)
1309 continue;
1310
1311 if (versions[i].crc == maybe_relocated(*crc, crc_owner))
1312 return 1;
1313 pr_debug("Found checksum %lX vs module %lX\n",
1314 maybe_relocated(*crc, crc_owner), versions[i].crc);
1315 goto bad_version;
1316 }
1317
1318 pr_warn("%s: no symbol version for %s\n", mod->name, symname);
1319 return 0;
1320
1321 bad_version:
1322 pr_warn("%s: disagrees about version of symbol %s\n",
1323 mod->name, symname);
1324 return 0;
1325 }
1326
1327 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1328 unsigned int versindex,
1329 struct module *mod)
1330 {
1331 const unsigned long *crc;
1332
1333 /*
1334 * Since this should be found in kernel (which can't be removed), no
1335 * locking is necessary -- use preempt_disable() to placate lockdep.
1336 */
1337 preempt_disable();
1338 if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1339 &crc, true, false)) {
1340 preempt_enable();
1341 BUG();
1342 }
1343 preempt_enable();
1344 return check_version(sechdrs, versindex,
1345 VMLINUX_SYMBOL_STR(module_layout), mod, crc,
1346 NULL);
1347 }
1348
1349 /* First part is kernel version, which we ignore if module has crcs. */
1350 static inline int same_magic(const char *amagic, const char *bmagic,
1351 bool has_crcs)
1352 {
1353 if (has_crcs) {
1354 amagic += strcspn(amagic, " ");
1355 bmagic += strcspn(bmagic, " ");
1356 }
1357 return strcmp(amagic, bmagic) == 0;
1358 }
1359 #else
1360 static inline int check_version(Elf_Shdr *sechdrs,
1361 unsigned int versindex,
1362 const char *symname,
1363 struct module *mod,
1364 const unsigned long *crc,
1365 const struct module *crc_owner)
1366 {
1367 return 1;
1368 }
1369
1370 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1371 unsigned int versindex,
1372 struct module *mod)
1373 {
1374 return 1;
1375 }
1376
1377 static inline int same_magic(const char *amagic, const char *bmagic,
1378 bool has_crcs)
1379 {
1380 return strcmp(amagic, bmagic) == 0;
1381 }
1382 #endif /* CONFIG_MODVERSIONS */
1383
1384 /* Resolve a symbol for this module. I.e. if we find one, record usage. */
1385 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1386 const struct load_info *info,
1387 const char *name,
1388 char ownername[])
1389 {
1390 struct module *owner;
1391 const struct kernel_symbol *sym;
1392 const unsigned long *crc;
1393 int err;
1394
1395 /*
1396 * The module_mutex should not be a heavily contended lock;
1397 * if we get the occasional sleep here, we'll go an extra iteration
1398 * in the wait_event_interruptible(), which is harmless.
1399 */
1400 sched_annotate_sleep();
1401 mutex_lock(&module_mutex);
1402 sym = find_symbol(name, &owner, &crc,
1403 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1404 if (!sym)
1405 goto unlock;
1406
1407 if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1408 owner)) {
1409 sym = ERR_PTR(-EINVAL);
1410 goto getname;
1411 }
1412
1413 err = ref_module(mod, owner);
1414 if (err) {
1415 sym = ERR_PTR(err);
1416 goto getname;
1417 }
1418
1419 getname:
1420 /* We must make copy under the lock if we failed to get ref. */
1421 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1422 unlock:
1423 mutex_unlock(&module_mutex);
1424 return sym;
1425 }
1426
1427 static const struct kernel_symbol *
1428 resolve_symbol_wait(struct module *mod,
1429 const struct load_info *info,
1430 const char *name)
1431 {
1432 const struct kernel_symbol *ksym;
1433 char owner[MODULE_NAME_LEN];
1434
1435 if (wait_event_interruptible_timeout(module_wq,
1436 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1437 || PTR_ERR(ksym) != -EBUSY,
1438 30 * HZ) <= 0) {
1439 pr_warn("%s: gave up waiting for init of module %s.\n",
1440 mod->name, owner);
1441 }
1442 return ksym;
1443 }
1444
1445 /*
1446 * /sys/module/foo/sections stuff
1447 * J. Corbet <corbet@lwn.net>
1448 */
1449 #ifdef CONFIG_SYSFS
1450
1451 #ifdef CONFIG_KALLSYMS
1452 static inline bool sect_empty(const Elf_Shdr *sect)
1453 {
1454 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1455 }
1456
1457 struct module_sect_attr {
1458 struct module_attribute mattr;
1459 char *name;
1460 unsigned long address;
1461 };
1462
1463 struct module_sect_attrs {
1464 struct attribute_group grp;
1465 unsigned int nsections;
1466 struct module_sect_attr attrs[0];
1467 };
1468
1469 static ssize_t module_sect_show(struct module_attribute *mattr,
1470 struct module_kobject *mk, char *buf)
1471 {
1472 struct module_sect_attr *sattr =
1473 container_of(mattr, struct module_sect_attr, mattr);
1474 return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1475 }
1476
1477 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1478 {
1479 unsigned int section;
1480
1481 for (section = 0; section < sect_attrs->nsections; section++)
1482 kfree(sect_attrs->attrs[section].name);
1483 kfree(sect_attrs);
1484 }
1485
1486 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1487 {
1488 unsigned int nloaded = 0, i, size[2];
1489 struct module_sect_attrs *sect_attrs;
1490 struct module_sect_attr *sattr;
1491 struct attribute **gattr;
1492
1493 /* Count loaded sections and allocate structures */
1494 for (i = 0; i < info->hdr->e_shnum; i++)
1495 if (!sect_empty(&info->sechdrs[i]))
1496 nloaded++;
1497 size[0] = ALIGN(sizeof(*sect_attrs)
1498 + nloaded * sizeof(sect_attrs->attrs[0]),
1499 sizeof(sect_attrs->grp.attrs[0]));
1500 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1501 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1502 if (sect_attrs == NULL)
1503 return;
1504
1505 /* Setup section attributes. */
1506 sect_attrs->grp.name = "sections";
1507 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1508
1509 sect_attrs->nsections = 0;
1510 sattr = &sect_attrs->attrs[0];
1511 gattr = &sect_attrs->grp.attrs[0];
1512 for (i = 0; i < info->hdr->e_shnum; i++) {
1513 Elf_Shdr *sec = &info->sechdrs[i];
1514 if (sect_empty(sec))
1515 continue;
1516 sattr->address = sec->sh_addr;
1517 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1518 GFP_KERNEL);
1519 if (sattr->name == NULL)
1520 goto out;
1521 sect_attrs->nsections++;
1522 sysfs_attr_init(&sattr->mattr.attr);
1523 sattr->mattr.show = module_sect_show;
1524 sattr->mattr.store = NULL;
1525 sattr->mattr.attr.name = sattr->name;
1526 sattr->mattr.attr.mode = S_IRUGO;
1527 *(gattr++) = &(sattr++)->mattr.attr;
1528 }
1529 *gattr = NULL;
1530
1531 if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1532 goto out;
1533
1534 mod->sect_attrs = sect_attrs;
1535 return;
1536 out:
1537 free_sect_attrs(sect_attrs);
1538 }
1539
1540 static void remove_sect_attrs(struct module *mod)
1541 {
1542 if (mod->sect_attrs) {
1543 sysfs_remove_group(&mod->mkobj.kobj,
1544 &mod->sect_attrs->grp);
1545 /* We are positive that no one is using any sect attrs
1546 * at this point. Deallocate immediately. */
1547 free_sect_attrs(mod->sect_attrs);
1548 mod->sect_attrs = NULL;
1549 }
1550 }
1551
1552 /*
1553 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1554 */
1555
1556 struct module_notes_attrs {
1557 struct kobject *dir;
1558 unsigned int notes;
1559 struct bin_attribute attrs[0];
1560 };
1561
1562 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1563 struct bin_attribute *bin_attr,
1564 char *buf, loff_t pos, size_t count)
1565 {
1566 /*
1567 * The caller checked the pos and count against our size.
1568 */
1569 memcpy(buf, bin_attr->private + pos, count);
1570 return count;
1571 }
1572
1573 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1574 unsigned int i)
1575 {
1576 if (notes_attrs->dir) {
1577 while (i-- > 0)
1578 sysfs_remove_bin_file(notes_attrs->dir,
1579 &notes_attrs->attrs[i]);
1580 kobject_put(notes_attrs->dir);
1581 }
1582 kfree(notes_attrs);
1583 }
1584
1585 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1586 {
1587 unsigned int notes, loaded, i;
1588 struct module_notes_attrs *notes_attrs;
1589 struct bin_attribute *nattr;
1590
1591 /* failed to create section attributes, so can't create notes */
1592 if (!mod->sect_attrs)
1593 return;
1594
1595 /* Count notes sections and allocate structures. */
1596 notes = 0;
1597 for (i = 0; i < info->hdr->e_shnum; i++)
1598 if (!sect_empty(&info->sechdrs[i]) &&
1599 (info->sechdrs[i].sh_type == SHT_NOTE))
1600 ++notes;
1601
1602 if (notes == 0)
1603 return;
1604
1605 notes_attrs = kzalloc(sizeof(*notes_attrs)
1606 + notes * sizeof(notes_attrs->attrs[0]),
1607 GFP_KERNEL);
1608 if (notes_attrs == NULL)
1609 return;
1610
1611 notes_attrs->notes = notes;
1612 nattr = &notes_attrs->attrs[0];
1613 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1614 if (sect_empty(&info->sechdrs[i]))
1615 continue;
1616 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1617 sysfs_bin_attr_init(nattr);
1618 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1619 nattr->attr.mode = S_IRUGO;
1620 nattr->size = info->sechdrs[i].sh_size;
1621 nattr->private = (void *) info->sechdrs[i].sh_addr;
1622 nattr->read = module_notes_read;
1623 ++nattr;
1624 }
1625 ++loaded;
1626 }
1627
1628 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1629 if (!notes_attrs->dir)
1630 goto out;
1631
1632 for (i = 0; i < notes; ++i)
1633 if (sysfs_create_bin_file(notes_attrs->dir,
1634 &notes_attrs->attrs[i]))
1635 goto out;
1636
1637 mod->notes_attrs = notes_attrs;
1638 return;
1639
1640 out:
1641 free_notes_attrs(notes_attrs, i);
1642 }
1643
1644 static void remove_notes_attrs(struct module *mod)
1645 {
1646 if (mod->notes_attrs)
1647 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1648 }
1649
1650 #else
1651
1652 static inline void add_sect_attrs(struct module *mod,
1653 const struct load_info *info)
1654 {
1655 }
1656
1657 static inline void remove_sect_attrs(struct module *mod)
1658 {
1659 }
1660
1661 static inline void add_notes_attrs(struct module *mod,
1662 const struct load_info *info)
1663 {
1664 }
1665
1666 static inline void remove_notes_attrs(struct module *mod)
1667 {
1668 }
1669 #endif /* CONFIG_KALLSYMS */
1670
1671 static void add_usage_links(struct module *mod)
1672 {
1673 #ifdef CONFIG_MODULE_UNLOAD
1674 struct module_use *use;
1675 int nowarn;
1676
1677 mutex_lock(&module_mutex);
1678 list_for_each_entry(use, &mod->target_list, target_list) {
1679 nowarn = sysfs_create_link(use->target->holders_dir,
1680 &mod->mkobj.kobj, mod->name);
1681 }
1682 mutex_unlock(&module_mutex);
1683 #endif
1684 }
1685
1686 static void del_usage_links(struct module *mod)
1687 {
1688 #ifdef CONFIG_MODULE_UNLOAD
1689 struct module_use *use;
1690
1691 mutex_lock(&module_mutex);
1692 list_for_each_entry(use, &mod->target_list, target_list)
1693 sysfs_remove_link(use->target->holders_dir, mod->name);
1694 mutex_unlock(&module_mutex);
1695 #endif
1696 }
1697
1698 static int module_add_modinfo_attrs(struct module *mod)
1699 {
1700 struct module_attribute *attr;
1701 struct module_attribute *temp_attr;
1702 int error = 0;
1703 int i;
1704
1705 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1706 (ARRAY_SIZE(modinfo_attrs) + 1)),
1707 GFP_KERNEL);
1708 if (!mod->modinfo_attrs)
1709 return -ENOMEM;
1710
1711 temp_attr = mod->modinfo_attrs;
1712 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1713 if (!attr->test ||
1714 (attr->test && attr->test(mod))) {
1715 memcpy(temp_attr, attr, sizeof(*temp_attr));
1716 sysfs_attr_init(&temp_attr->attr);
1717 error = sysfs_create_file(&mod->mkobj.kobj,
1718 &temp_attr->attr);
1719 ++temp_attr;
1720 }
1721 }
1722 return error;
1723 }
1724
1725 static void module_remove_modinfo_attrs(struct module *mod)
1726 {
1727 struct module_attribute *attr;
1728 int i;
1729
1730 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1731 /* pick a field to test for end of list */
1732 if (!attr->attr.name)
1733 break;
1734 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1735 if (attr->free)
1736 attr->free(mod);
1737 }
1738 kfree(mod->modinfo_attrs);
1739 }
1740
1741 static void mod_kobject_put(struct module *mod)
1742 {
1743 DECLARE_COMPLETION_ONSTACK(c);
1744 mod->mkobj.kobj_completion = &c;
1745 kobject_put(&mod->mkobj.kobj);
1746 wait_for_completion(&c);
1747 }
1748
1749 static int mod_sysfs_init(struct module *mod)
1750 {
1751 int err;
1752 struct kobject *kobj;
1753
1754 if (!module_sysfs_initialized) {
1755 pr_err("%s: module sysfs not initialized\n", mod->name);
1756 err = -EINVAL;
1757 goto out;
1758 }
1759
1760 kobj = kset_find_obj(module_kset, mod->name);
1761 if (kobj) {
1762 pr_err("%s: module is already loaded\n", mod->name);
1763 kobject_put(kobj);
1764 err = -EINVAL;
1765 goto out;
1766 }
1767
1768 mod->mkobj.mod = mod;
1769
1770 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1771 mod->mkobj.kobj.kset = module_kset;
1772 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1773 "%s", mod->name);
1774 if (err)
1775 mod_kobject_put(mod);
1776
1777 /* delay uevent until full sysfs population */
1778 out:
1779 return err;
1780 }
1781
1782 static int mod_sysfs_setup(struct module *mod,
1783 const struct load_info *info,
1784 struct kernel_param *kparam,
1785 unsigned int num_params)
1786 {
1787 int err;
1788
1789 err = mod_sysfs_init(mod);
1790 if (err)
1791 goto out;
1792
1793 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1794 if (!mod->holders_dir) {
1795 err = -ENOMEM;
1796 goto out_unreg;
1797 }
1798
1799 err = module_param_sysfs_setup(mod, kparam, num_params);
1800 if (err)
1801 goto out_unreg_holders;
1802
1803 err = module_add_modinfo_attrs(mod);
1804 if (err)
1805 goto out_unreg_param;
1806
1807 add_usage_links(mod);
1808 add_sect_attrs(mod, info);
1809 add_notes_attrs(mod, info);
1810
1811 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1812 return 0;
1813
1814 out_unreg_param:
1815 module_param_sysfs_remove(mod);
1816 out_unreg_holders:
1817 kobject_put(mod->holders_dir);
1818 out_unreg:
1819 mod_kobject_put(mod);
1820 out:
1821 return err;
1822 }
1823
1824 static void mod_sysfs_fini(struct module *mod)
1825 {
1826 remove_notes_attrs(mod);
1827 remove_sect_attrs(mod);
1828 mod_kobject_put(mod);
1829 }
1830
1831 static void init_param_lock(struct module *mod)
1832 {
1833 mutex_init(&mod->param_lock);
1834 }
1835 #else /* !CONFIG_SYSFS */
1836
1837 static int mod_sysfs_setup(struct module *mod,
1838 const struct load_info *info,
1839 struct kernel_param *kparam,
1840 unsigned int num_params)
1841 {
1842 return 0;
1843 }
1844
1845 static void mod_sysfs_fini(struct module *mod)
1846 {
1847 }
1848
1849 static void module_remove_modinfo_attrs(struct module *mod)
1850 {
1851 }
1852
1853 static void del_usage_links(struct module *mod)
1854 {
1855 }
1856
1857 static void init_param_lock(struct module *mod)
1858 {
1859 }
1860 #endif /* CONFIG_SYSFS */
1861
1862 static void mod_sysfs_teardown(struct module *mod)
1863 {
1864 del_usage_links(mod);
1865 module_remove_modinfo_attrs(mod);
1866 module_param_sysfs_remove(mod);
1867 kobject_put(mod->mkobj.drivers_dir);
1868 kobject_put(mod->holders_dir);
1869 mod_sysfs_fini(mod);
1870 }
1871
1872 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
1873 /*
1874 * LKM RO/NX protection: protect module's text/ro-data
1875 * from modification and any data from execution.
1876 */
1877 void set_page_attributes(void *start, void *end, int (*set)(unsigned long start, int num_pages))
1878 {
1879 unsigned long begin_pfn = PFN_DOWN((unsigned long)start);
1880 unsigned long end_pfn = PFN_DOWN((unsigned long)end);
1881
1882 if (end_pfn > begin_pfn)
1883 set(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1884 }
1885
1886 static void set_section_ro_nx(void *base,
1887 unsigned long text_size,
1888 unsigned long ro_size,
1889 unsigned long total_size)
1890 {
1891 /* begin and end PFNs of the current subsection */
1892 unsigned long begin_pfn;
1893 unsigned long end_pfn;
1894
1895 /*
1896 * Set RO for module text and RO-data:
1897 * - Always protect first page.
1898 * - Do not protect last partial page.
1899 */
1900 if (ro_size > 0)
1901 set_page_attributes(base, base + ro_size, set_memory_ro);
1902
1903 /*
1904 * Set NX permissions for module data:
1905 * - Do not protect first partial page.
1906 * - Always protect last page.
1907 */
1908 if (total_size > text_size) {
1909 begin_pfn = PFN_UP((unsigned long)base + text_size);
1910 end_pfn = PFN_UP((unsigned long)base + total_size);
1911 if (end_pfn > begin_pfn)
1912 set_memory_nx(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1913 }
1914 }
1915
1916 static void unset_module_core_ro_nx(struct module *mod)
1917 {
1918 set_page_attributes(mod->module_core + mod->core_text_size,
1919 mod->module_core + mod->core_size,
1920 set_memory_x);
1921 set_page_attributes(mod->module_core,
1922 mod->module_core + mod->core_ro_size,
1923 set_memory_rw);
1924 }
1925
1926 static void unset_module_init_ro_nx(struct module *mod)
1927 {
1928 set_page_attributes(mod->module_init + mod->init_text_size,
1929 mod->module_init + mod->init_size,
1930 set_memory_x);
1931 set_page_attributes(mod->module_init,
1932 mod->module_init + mod->init_ro_size,
1933 set_memory_rw);
1934 }
1935
1936 /* Iterate through all modules and set each module's text as RW */
1937 void set_all_modules_text_rw(void)
1938 {
1939 struct module *mod;
1940
1941 mutex_lock(&module_mutex);
1942 list_for_each_entry_rcu(mod, &modules, list) {
1943 if (mod->state == MODULE_STATE_UNFORMED)
1944 continue;
1945 if ((mod->module_core) && (mod->core_text_size)) {
1946 set_page_attributes(mod->module_core,
1947 mod->module_core + mod->core_text_size,
1948 set_memory_rw);
1949 }
1950 if ((mod->module_init) && (mod->init_text_size)) {
1951 set_page_attributes(mod->module_init,
1952 mod->module_init + mod->init_text_size,
1953 set_memory_rw);
1954 }
1955 }
1956 mutex_unlock(&module_mutex);
1957 }
1958
1959 /* Iterate through all modules and set each module's text as RO */
1960 void set_all_modules_text_ro(void)
1961 {
1962 struct module *mod;
1963
1964 mutex_lock(&module_mutex);
1965 list_for_each_entry_rcu(mod, &modules, list) {
1966 if (mod->state == MODULE_STATE_UNFORMED)
1967 continue;
1968 if ((mod->module_core) && (mod->core_text_size)) {
1969 set_page_attributes(mod->module_core,
1970 mod->module_core + mod->core_text_size,
1971 set_memory_ro);
1972 }
1973 if ((mod->module_init) && (mod->init_text_size)) {
1974 set_page_attributes(mod->module_init,
1975 mod->module_init + mod->init_text_size,
1976 set_memory_ro);
1977 }
1978 }
1979 mutex_unlock(&module_mutex);
1980 }
1981 #else
1982 static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { }
1983 static void unset_module_core_ro_nx(struct module *mod) { }
1984 static void unset_module_init_ro_nx(struct module *mod) { }
1985 #endif
1986
1987 void __weak module_memfree(void *module_region)
1988 {
1989 vfree(module_region);
1990 }
1991
1992 void __weak module_arch_cleanup(struct module *mod)
1993 {
1994 }
1995
1996 void __weak module_arch_freeing_init(struct module *mod)
1997 {
1998 }
1999
2000 /* Free a module, remove from lists, etc. */
2001 static void free_module(struct module *mod)
2002 {
2003 trace_module_free(mod);
2004
2005 mod_sysfs_teardown(mod);
2006
2007 /* We leave it in list to prevent duplicate loads, but make sure
2008 * that noone uses it while it's being deconstructed. */
2009 mutex_lock(&module_mutex);
2010 mod->state = MODULE_STATE_UNFORMED;
2011 mutex_unlock(&module_mutex);
2012
2013 /* Remove dynamic debug info */
2014 ddebug_remove_module(mod->name);
2015
2016 /* Arch-specific cleanup. */
2017 module_arch_cleanup(mod);
2018
2019 /* Module unload stuff */
2020 module_unload_free(mod);
2021
2022 /* Free any allocated parameters. */
2023 destroy_params(mod->kp, mod->num_kp);
2024
2025 /* Now we can delete it from the lists */
2026 mutex_lock(&module_mutex);
2027 /* Unlink carefully: kallsyms could be walking list. */
2028 list_del_rcu(&mod->list);
2029 mod_tree_remove(mod);
2030 /* Remove this module from bug list, this uses list_del_rcu */
2031 module_bug_cleanup(mod);
2032 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2033 synchronize_sched();
2034 mutex_unlock(&module_mutex);
2035
2036 /* This may be NULL, but that's OK */
2037 unset_module_init_ro_nx(mod);
2038 module_arch_freeing_init(mod);
2039 module_memfree(mod->module_init);
2040 kfree(mod->args);
2041 percpu_modfree(mod);
2042
2043 /* Free lock-classes; relies on the preceding sync_rcu(). */
2044 lockdep_free_key_range(mod->module_core, mod->core_size);
2045
2046 /* Finally, free the core (containing the module structure) */
2047 unset_module_core_ro_nx(mod);
2048 module_memfree(mod->module_core);
2049
2050 #ifdef CONFIG_MPU
2051 update_protections(current->mm);
2052 #endif
2053 }
2054
2055 void *__symbol_get(const char *symbol)
2056 {
2057 struct module *owner;
2058 const struct kernel_symbol *sym;
2059
2060 preempt_disable();
2061 sym = find_symbol(symbol, &owner, NULL, true, true);
2062 if (sym && strong_try_module_get(owner))
2063 sym = NULL;
2064 preempt_enable();
2065
2066 return sym ? (void *)sym->value : NULL;
2067 }
2068 EXPORT_SYMBOL_GPL(__symbol_get);
2069
2070 /*
2071 * Ensure that an exported symbol [global namespace] does not already exist
2072 * in the kernel or in some other module's exported symbol table.
2073 *
2074 * You must hold the module_mutex.
2075 */
2076 static int verify_export_symbols(struct module *mod)
2077 {
2078 unsigned int i;
2079 struct module *owner;
2080 const struct kernel_symbol *s;
2081 struct {
2082 const struct kernel_symbol *sym;
2083 unsigned int num;
2084 } arr[] = {
2085 { mod->syms, mod->num_syms },
2086 { mod->gpl_syms, mod->num_gpl_syms },
2087 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2088 #ifdef CONFIG_UNUSED_SYMBOLS
2089 { mod->unused_syms, mod->num_unused_syms },
2090 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2091 #endif
2092 };
2093
2094 for (i = 0; i < ARRAY_SIZE(arr); i++) {
2095 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2096 if (find_symbol(s->name, &owner, NULL, true, false)) {
2097 pr_err("%s: exports duplicate symbol %s"
2098 " (owned by %s)\n",
2099 mod->name, s->name, module_name(owner));
2100 return -ENOEXEC;
2101 }
2102 }
2103 }
2104 return 0;
2105 }
2106
2107 /* Change all symbols so that st_value encodes the pointer directly. */
2108 static int simplify_symbols(struct module *mod, const struct load_info *info)
2109 {
2110 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2111 Elf_Sym *sym = (void *)symsec->sh_addr;
2112 unsigned long secbase;
2113 unsigned int i;
2114 int ret = 0;
2115 const struct kernel_symbol *ksym;
2116
2117 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2118 const char *name = info->strtab + sym[i].st_name;
2119
2120 switch (sym[i].st_shndx) {
2121 case SHN_COMMON:
2122 /* Ignore common symbols */
2123 if (!strncmp(name, "__gnu_lto", 9))
2124 break;
2125
2126 /* We compiled with -fno-common. These are not
2127 supposed to happen. */
2128 pr_debug("Common symbol: %s\n", name);
2129 pr_warn("%s: please compile with -fno-common\n",
2130 mod->name);
2131 ret = -ENOEXEC;
2132 break;
2133
2134 case SHN_ABS:
2135 /* Don't need to do anything */
2136 pr_debug("Absolute symbol: 0x%08lx\n",
2137 (long)sym[i].st_value);
2138 break;
2139
2140 case SHN_UNDEF:
2141 ksym = resolve_symbol_wait(mod, info, name);
2142 /* Ok if resolved. */
2143 if (ksym && !IS_ERR(ksym)) {
2144 sym[i].st_value = ksym->value;
2145 break;
2146 }
2147
2148 /* Ok if weak. */
2149 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2150 break;
2151
2152 pr_warn("%s: Unknown symbol %s (err %li)\n",
2153 mod->name, name, PTR_ERR(ksym));
2154 ret = PTR_ERR(ksym) ?: -ENOENT;
2155 break;
2156
2157 default:
2158 /* Divert to percpu allocation if a percpu var. */
2159 if (sym[i].st_shndx == info->index.pcpu)
2160 secbase = (unsigned long)mod_percpu(mod);
2161 else
2162 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2163 sym[i].st_value += secbase;
2164 break;
2165 }
2166 }
2167
2168 return ret;
2169 }
2170
2171 static int apply_relocations(struct module *mod, const struct load_info *info)
2172 {
2173 unsigned int i;
2174 int err = 0;
2175
2176 /* Now do relocations. */
2177 for (i = 1; i < info->hdr->e_shnum; i++) {
2178 unsigned int infosec = info->sechdrs[i].sh_info;
2179
2180 /* Not a valid relocation section? */
2181 if (infosec >= info->hdr->e_shnum)
2182 continue;
2183
2184 /* Don't bother with non-allocated sections */
2185 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2186 continue;
2187
2188 if (info->sechdrs[i].sh_type == SHT_REL)
2189 err = apply_relocate(info->sechdrs, info->strtab,
2190 info->index.sym, i, mod);
2191 else if (info->sechdrs[i].sh_type == SHT_RELA)
2192 err = apply_relocate_add(info->sechdrs, info->strtab,
2193 info->index.sym, i, mod);
2194 if (err < 0)
2195 break;
2196 }
2197 return err;
2198 }
2199
2200 /* Additional bytes needed by arch in front of individual sections */
2201 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2202 unsigned int section)
2203 {
2204 /* default implementation just returns zero */
2205 return 0;
2206 }
2207
2208 /* Update size with this section: return offset. */
2209 static long get_offset(struct module *mod, unsigned int *size,
2210 Elf_Shdr *sechdr, unsigned int section)
2211 {
2212 long ret;
2213
2214 *size += arch_mod_section_prepend(mod, section);
2215 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2216 *size = ret + sechdr->sh_size;
2217 return ret;
2218 }
2219
2220 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2221 might -- code, read-only data, read-write data, small data. Tally
2222 sizes, and place the offsets into sh_entsize fields: high bit means it
2223 belongs in init. */
2224 static void layout_sections(struct module *mod, struct load_info *info)
2225 {
2226 static unsigned long const masks[][2] = {
2227 /* NOTE: all executable code must be the first section
2228 * in this array; otherwise modify the text_size
2229 * finder in the two loops below */
2230 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2231 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2232 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2233 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2234 };
2235 unsigned int m, i;
2236
2237 for (i = 0; i < info->hdr->e_shnum; i++)
2238 info->sechdrs[i].sh_entsize = ~0UL;
2239
2240 pr_debug("Core section allocation order:\n");
2241 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2242 for (i = 0; i < info->hdr->e_shnum; ++i) {
2243 Elf_Shdr *s = &info->sechdrs[i];
2244 const char *sname = info->secstrings + s->sh_name;
2245
2246 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2247 || (s->sh_flags & masks[m][1])
2248 || s->sh_entsize != ~0UL
2249 || strstarts(sname, ".init"))
2250 continue;
2251 s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
2252 pr_debug("\t%s\n", sname);
2253 }
2254 switch (m) {
2255 case 0: /* executable */
2256 mod->core_size = debug_align(mod->core_size);
2257 mod->core_text_size = mod->core_size;
2258 break;
2259 case 1: /* RO: text and ro-data */
2260 mod->core_size = debug_align(mod->core_size);
2261 mod->core_ro_size = mod->core_size;
2262 break;
2263 case 3: /* whole core */
2264 mod->core_size = debug_align(mod->core_size);
2265 break;
2266 }
2267 }
2268
2269 pr_debug("Init section allocation order:\n");
2270 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2271 for (i = 0; i < info->hdr->e_shnum; ++i) {
2272 Elf_Shdr *s = &info->sechdrs[i];
2273 const char *sname = info->secstrings + s->sh_name;
2274
2275 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2276 || (s->sh_flags & masks[m][1])
2277 || s->sh_entsize != ~0UL
2278 || !strstarts(sname, ".init"))
2279 continue;
2280 s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
2281 | INIT_OFFSET_MASK);
2282 pr_debug("\t%s\n", sname);
2283 }
2284 switch (m) {
2285 case 0: /* executable */
2286 mod->init_size = debug_align(mod->init_size);
2287 mod->init_text_size = mod->init_size;
2288 break;
2289 case 1: /* RO: text and ro-data */
2290 mod->init_size = debug_align(mod->init_size);
2291 mod->init_ro_size = mod->init_size;
2292 break;
2293 case 3: /* whole init */
2294 mod->init_size = debug_align(mod->init_size);
2295 break;
2296 }
2297 }
2298 }
2299
2300 static void set_license(struct module *mod, const char *license)
2301 {
2302 if (!license)
2303 license = "unspecified";
2304
2305 if (!license_is_gpl_compatible(license)) {
2306 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2307 pr_warn("%s: module license '%s' taints kernel.\n",
2308 mod->name, license);
2309 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2310 LOCKDEP_NOW_UNRELIABLE);
2311 }
2312 }
2313
2314 /* Parse tag=value strings from .modinfo section */
2315 static char *next_string(char *string, unsigned long *secsize)
2316 {
2317 /* Skip non-zero chars */
2318 while (string[0]) {
2319 string++;
2320 if ((*secsize)-- <= 1)
2321 return NULL;
2322 }
2323
2324 /* Skip any zero padding. */
2325 while (!string[0]) {
2326 string++;
2327 if ((*secsize)-- <= 1)
2328 return NULL;
2329 }
2330 return string;
2331 }
2332
2333 static char *get_modinfo(struct load_info *info, const char *tag)
2334 {
2335 char *p;
2336 unsigned int taglen = strlen(tag);
2337 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2338 unsigned long size = infosec->sh_size;
2339
2340 for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2341 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2342 return p + taglen + 1;
2343 }
2344 return NULL;
2345 }
2346
2347 static void setup_modinfo(struct module *mod, struct load_info *info)
2348 {
2349 struct module_attribute *attr;
2350 int i;
2351
2352 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2353 if (attr->setup)
2354 attr->setup(mod, get_modinfo(info, attr->attr.name));
2355 }
2356 }
2357
2358 static void free_modinfo(struct module *mod)
2359 {
2360 struct module_attribute *attr;
2361 int i;
2362
2363 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2364 if (attr->free)
2365 attr->free(mod);
2366 }
2367 }
2368
2369 #ifdef CONFIG_KALLSYMS
2370
2371 /* lookup symbol in given range of kernel_symbols */
2372 static const struct kernel_symbol *lookup_symbol(const char *name,
2373 const struct kernel_symbol *start,
2374 const struct kernel_symbol *stop)
2375 {
2376 return bsearch(name, start, stop - start,
2377 sizeof(struct kernel_symbol), cmp_name);
2378 }
2379
2380 static int is_exported(const char *name, unsigned long value,
2381 const struct module *mod)
2382 {
2383 const struct kernel_symbol *ks;
2384 if (!mod)
2385 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2386 else
2387 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2388 return ks != NULL && ks->value == value;
2389 }
2390
2391 /* As per nm */
2392 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2393 {
2394 const Elf_Shdr *sechdrs = info->sechdrs;
2395
2396 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2397 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2398 return 'v';
2399 else
2400 return 'w';
2401 }
2402 if (sym->st_shndx == SHN_UNDEF)
2403 return 'U';
2404 if (sym->st_shndx == SHN_ABS)
2405 return 'a';
2406 if (sym->st_shndx >= SHN_LORESERVE)
2407 return '?';
2408 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2409 return 't';
2410 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2411 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2412 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2413 return 'r';
2414 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2415 return 'g';
2416 else
2417 return 'd';
2418 }
2419 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2420 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2421 return 's';
2422 else
2423 return 'b';
2424 }
2425 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2426 ".debug")) {
2427 return 'n';
2428 }
2429 return '?';
2430 }
2431
2432 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2433 unsigned int shnum)
2434 {
2435 const Elf_Shdr *sec;
2436
2437 if (src->st_shndx == SHN_UNDEF
2438 || src->st_shndx >= shnum
2439 || !src->st_name)
2440 return false;
2441
2442 sec = sechdrs + src->st_shndx;
2443 if (!(sec->sh_flags & SHF_ALLOC)
2444 #ifndef CONFIG_KALLSYMS_ALL
2445 || !(sec->sh_flags & SHF_EXECINSTR)
2446 #endif
2447 || (sec->sh_entsize & INIT_OFFSET_MASK))
2448 return false;
2449
2450 return true;
2451 }
2452
2453 /*
2454 * We only allocate and copy the strings needed by the parts of symtab
2455 * we keep. This is simple, but has the effect of making multiple
2456 * copies of duplicates. We could be more sophisticated, see
2457 * linux-kernel thread starting with
2458 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2459 */
2460 static void layout_symtab(struct module *mod, struct load_info *info)
2461 {
2462 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2463 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2464 const Elf_Sym *src;
2465 unsigned int i, nsrc, ndst, strtab_size = 0;
2466
2467 /* Put symbol section at end of init part of module. */
2468 symsect->sh_flags |= SHF_ALLOC;
2469 symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
2470 info->index.sym) | INIT_OFFSET_MASK;
2471 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2472
2473 src = (void *)info->hdr + symsect->sh_offset;
2474 nsrc = symsect->sh_size / sizeof(*src);
2475
2476 /* Compute total space required for the core symbols' strtab. */
2477 for (ndst = i = 0; i < nsrc; i++) {
2478 if (i == 0 ||
2479 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
2480 strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2481 ndst++;
2482 }
2483 }
2484
2485 /* Append room for core symbols at end of core part. */
2486 info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2487 info->stroffs = mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
2488 mod->core_size += strtab_size;
2489 mod->core_size = debug_align(mod->core_size);
2490
2491 /* Put string table section at end of init part of module. */
2492 strsect->sh_flags |= SHF_ALLOC;
2493 strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
2494 info->index.str) | INIT_OFFSET_MASK;
2495 mod->init_size = debug_align(mod->init_size);
2496 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2497 }
2498
2499 static void add_kallsyms(struct module *mod, const struct load_info *info)
2500 {
2501 unsigned int i, ndst;
2502 const Elf_Sym *src;
2503 Elf_Sym *dst;
2504 char *s;
2505 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2506
2507 mod->symtab = (void *)symsec->sh_addr;
2508 mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2509 /* Make sure we get permanent strtab: don't use info->strtab. */
2510 mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2511
2512 /* Set types up while we still have access to sections. */
2513 for (i = 0; i < mod->num_symtab; i++)
2514 mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2515
2516 mod->core_symtab = dst = mod->module_core + info->symoffs;
2517 mod->core_strtab = s = mod->module_core + info->stroffs;
2518 src = mod->symtab;
2519 for (ndst = i = 0; i < mod->num_symtab; i++) {
2520 if (i == 0 ||
2521 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
2522 dst[ndst] = src[i];
2523 dst[ndst++].st_name = s - mod->core_strtab;
2524 s += strlcpy(s, &mod->strtab[src[i].st_name],
2525 KSYM_NAME_LEN) + 1;
2526 }
2527 }
2528 mod->core_num_syms = ndst;
2529 }
2530 #else
2531 static inline void layout_symtab(struct module *mod, struct load_info *info)
2532 {
2533 }
2534
2535 static void add_kallsyms(struct module *mod, const struct load_info *info)
2536 {
2537 }
2538 #endif /* CONFIG_KALLSYMS */
2539
2540 static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2541 {
2542 if (!debug)
2543 return;
2544 #ifdef CONFIG_DYNAMIC_DEBUG
2545 if (ddebug_add_module(debug, num, debug->modname))
2546 pr_err("dynamic debug error adding module: %s\n",
2547 debug->modname);
2548 #endif
2549 }
2550
2551 static void dynamic_debug_remove(struct _ddebug *debug)
2552 {
2553 if (debug)
2554 ddebug_remove_module(debug->modname);
2555 }
2556
2557 void * __weak module_alloc(unsigned long size)
2558 {
2559 return vmalloc_exec(size);
2560 }
2561
2562 #ifdef CONFIG_DEBUG_KMEMLEAK
2563 static void kmemleak_load_module(const struct module *mod,
2564 const struct load_info *info)
2565 {
2566 unsigned int i;
2567
2568 /* only scan the sections containing data */
2569 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2570
2571 for (i = 1; i < info->hdr->e_shnum; i++) {
2572 /* Scan all writable sections that's not executable */
2573 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2574 !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2575 (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2576 continue;
2577
2578 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2579 info->sechdrs[i].sh_size, GFP_KERNEL);
2580 }
2581 }
2582 #else
2583 static inline void kmemleak_load_module(const struct module *mod,
2584 const struct load_info *info)
2585 {
2586 }
2587 #endif
2588
2589 #ifdef CONFIG_MODULE_SIG
2590 static int module_sig_check(struct load_info *info)
2591 {
2592 int err = -ENOKEY;
2593 const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2594 const void *mod = info->hdr;
2595
2596 if (info->len > markerlen &&
2597 memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2598 /* We truncate the module to discard the signature */
2599 info->len -= markerlen;
2600 err = mod_verify_sig(mod, &info->len);
2601 }
2602
2603 if (!err) {
2604 info->sig_ok = true;
2605 return 0;
2606 }
2607
2608 /* Not having a signature is only an error if we're strict. */
2609 if (err == -ENOKEY && !sig_enforce)
2610 err = 0;
2611
2612 return err;
2613 }
2614 #else /* !CONFIG_MODULE_SIG */
2615 static int module_sig_check(struct load_info *info)
2616 {
2617 return 0;
2618 }
2619 #endif /* !CONFIG_MODULE_SIG */
2620
2621 /* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2622 static int elf_header_check(struct load_info *info)
2623 {
2624 if (info->len < sizeof(*(info->hdr)))
2625 return -ENOEXEC;
2626
2627 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2628 || info->hdr->e_type != ET_REL
2629 || !elf_check_arch(info->hdr)
2630 || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2631 return -ENOEXEC;
2632
2633 if (info->hdr->e_shoff >= info->len
2634 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2635 info->len - info->hdr->e_shoff))
2636 return -ENOEXEC;
2637
2638 return 0;
2639 }
2640
2641 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2642
2643 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2644 {
2645 do {
2646 unsigned long n = min(len, COPY_CHUNK_SIZE);
2647
2648 if (copy_from_user(dst, usrc, n) != 0)
2649 return -EFAULT;
2650 cond_resched();
2651 dst += n;
2652 usrc += n;
2653 len -= n;
2654 } while (len);
2655 return 0;
2656 }
2657
2658 /* Sets info->hdr and info->len. */
2659 static int copy_module_from_user(const void __user *umod, unsigned long len,
2660 struct load_info *info)
2661 {
2662 int err;
2663
2664 info->len = len;
2665 if (info->len < sizeof(*(info->hdr)))
2666 return -ENOEXEC;
2667
2668 err = security_kernel_module_from_file(NULL);
2669 if (err)
2670 return err;
2671
2672 /* Suck in entire file: we'll want most of it. */
2673 info->hdr = __vmalloc(info->len,
2674 GFP_KERNEL | __GFP_HIGHMEM | __GFP_NOWARN, PAGE_KERNEL);
2675 if (!info->hdr)
2676 return -ENOMEM;
2677
2678 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2679 vfree(info->hdr);
2680 return -EFAULT;
2681 }
2682
2683 return 0;
2684 }
2685
2686 /* Sets info->hdr and info->len. */
2687 static int copy_module_from_fd(int fd, struct load_info *info)
2688 {
2689 struct fd f = fdget(fd);
2690 int err;
2691 struct kstat stat;
2692 loff_t pos;
2693 ssize_t bytes = 0;
2694
2695 if (!f.file)
2696 return -ENOEXEC;
2697
2698 err = security_kernel_module_from_file(f.file);
2699 if (err)
2700 goto out;
2701
2702 err = vfs_getattr(&f.file->f_path, &stat);
2703 if (err)
2704 goto out;
2705
2706 if (stat.size > INT_MAX) {
2707 err = -EFBIG;
2708 goto out;
2709 }
2710
2711 /* Don't hand 0 to vmalloc, it whines. */
2712 if (stat.size == 0) {
2713 err = -EINVAL;
2714 goto out;
2715 }
2716
2717 info->hdr = vmalloc(stat.size);
2718 if (!info->hdr) {
2719 err = -ENOMEM;
2720 goto out;
2721 }
2722
2723 pos = 0;
2724 while (pos < stat.size) {
2725 bytes = kernel_read(f.file, pos, (char *)(info->hdr) + pos,
2726 stat.size - pos);
2727 if (bytes < 0) {
2728 vfree(info->hdr);
2729 err = bytes;
2730 goto out;
2731 }
2732 if (bytes == 0)
2733 break;
2734 pos += bytes;
2735 }
2736 info->len = pos;
2737
2738 out:
2739 fdput(f);
2740 return err;
2741 }
2742
2743 static void free_copy(struct load_info *info)
2744 {
2745 vfree(info->hdr);
2746 }
2747
2748 static int rewrite_section_headers(struct load_info *info, int flags)
2749 {
2750 unsigned int i;
2751
2752 /* This should always be true, but let's be sure. */
2753 info->sechdrs[0].sh_addr = 0;
2754
2755 for (i = 1; i < info->hdr->e_shnum; i++) {
2756 Elf_Shdr *shdr = &info->sechdrs[i];
2757 if (shdr->sh_type != SHT_NOBITS
2758 && info->len < shdr->sh_offset + shdr->sh_size) {
2759 pr_err("Module len %lu truncated\n", info->len);
2760 return -ENOEXEC;
2761 }
2762
2763 /* Mark all sections sh_addr with their address in the
2764 temporary image. */
2765 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2766
2767 #ifndef CONFIG_MODULE_UNLOAD
2768 /* Don't load .exit sections */
2769 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2770 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2771 #endif
2772 }
2773
2774 /* Track but don't keep modinfo and version sections. */
2775 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2776 info->index.vers = 0; /* Pretend no __versions section! */
2777 else
2778 info->index.vers = find_sec(info, "__versions");
2779 info->index.info = find_sec(info, ".modinfo");
2780 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2781 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2782 return 0;
2783 }
2784
2785 /*
2786 * Set up our basic convenience variables (pointers to section headers,
2787 * search for module section index etc), and do some basic section
2788 * verification.
2789 *
2790 * Return the temporary module pointer (we'll replace it with the final
2791 * one when we move the module sections around).
2792 */
2793 static struct module *setup_load_info(struct load_info *info, int flags)
2794 {
2795 unsigned int i;
2796 int err;
2797 struct module *mod;
2798
2799 /* Set up the convenience variables */
2800 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2801 info->secstrings = (void *)info->hdr
2802 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2803
2804 err = rewrite_section_headers(info, flags);
2805 if (err)
2806 return ERR_PTR(err);
2807
2808 /* Find internal symbols and strings. */
2809 for (i = 1; i < info->hdr->e_shnum; i++) {
2810 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2811 info->index.sym = i;
2812 info->index.str = info->sechdrs[i].sh_link;
2813 info->strtab = (char *)info->hdr
2814 + info->sechdrs[info->index.str].sh_offset;
2815 break;
2816 }
2817 }
2818
2819 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2820 if (!info->index.mod) {
2821 pr_warn("No module found in object\n");
2822 return ERR_PTR(-ENOEXEC);
2823 }
2824 /* This is temporary: point mod into copy of data. */
2825 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2826
2827 if (info->index.sym == 0) {
2828 pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
2829 return ERR_PTR(-ENOEXEC);
2830 }
2831
2832 info->index.pcpu = find_pcpusec(info);
2833
2834 /* Check module struct version now, before we try to use module. */
2835 if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2836 return ERR_PTR(-ENOEXEC);
2837
2838 return mod;
2839 }
2840
2841 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2842 {
2843 const char *modmagic = get_modinfo(info, "vermagic");
2844 int err;
2845
2846 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2847 modmagic = NULL;
2848
2849 /* This is allowed: modprobe --force will invalidate it. */
2850 if (!modmagic) {
2851 err = try_to_force_load(mod, "bad vermagic");
2852 if (err)
2853 return err;
2854 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2855 pr_err("%s: version magic '%s' should be '%s'\n",
2856 mod->name, modmagic, vermagic);
2857 return -ENOEXEC;
2858 }
2859
2860 if (!get_modinfo(info, "intree"))
2861 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2862
2863 if (get_modinfo(info, "staging")) {
2864 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2865 pr_warn("%s: module is from the staging directory, the quality "
2866 "is unknown, you have been warned.\n", mod->name);
2867 }
2868
2869 /* Set up license info based on the info section */
2870 set_license(mod, get_modinfo(info, "license"));
2871
2872 return 0;
2873 }
2874
2875 static int find_module_sections(struct module *mod, struct load_info *info)
2876 {
2877 mod->kp = section_objs(info, "__param",
2878 sizeof(*mod->kp), &mod->num_kp);
2879 mod->syms = section_objs(info, "__ksymtab",
2880 sizeof(*mod->syms), &mod->num_syms);
2881 mod->crcs = section_addr(info, "__kcrctab");
2882 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2883 sizeof(*mod->gpl_syms),
2884 &mod->num_gpl_syms);
2885 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2886 mod->gpl_future_syms = section_objs(info,
2887 "__ksymtab_gpl_future",
2888 sizeof(*mod->gpl_future_syms),
2889 &mod->num_gpl_future_syms);
2890 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2891
2892 #ifdef CONFIG_UNUSED_SYMBOLS
2893 mod->unused_syms = section_objs(info, "__ksymtab_unused",
2894 sizeof(*mod->unused_syms),
2895 &mod->num_unused_syms);
2896 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
2897 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2898 sizeof(*mod->unused_gpl_syms),
2899 &mod->num_unused_gpl_syms);
2900 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2901 #endif
2902 #ifdef CONFIG_CONSTRUCTORS
2903 mod->ctors = section_objs(info, ".ctors",
2904 sizeof(*mod->ctors), &mod->num_ctors);
2905 if (!mod->ctors)
2906 mod->ctors = section_objs(info, ".init_array",
2907 sizeof(*mod->ctors), &mod->num_ctors);
2908 else if (find_sec(info, ".init_array")) {
2909 /*
2910 * This shouldn't happen with same compiler and binutils
2911 * building all parts of the module.
2912 */
2913 pr_warn("%s: has both .ctors and .init_array.\n",
2914 mod->name);
2915 return -EINVAL;
2916 }
2917 #endif
2918
2919 #ifdef CONFIG_TRACEPOINTS
2920 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2921 sizeof(*mod->tracepoints_ptrs),
2922 &mod->num_tracepoints);
2923 #endif
2924 #ifdef HAVE_JUMP_LABEL
2925 mod->jump_entries = section_objs(info, "__jump_table",
2926 sizeof(*mod->jump_entries),
2927 &mod->num_jump_entries);
2928 #endif
2929 #ifdef CONFIG_EVENT_TRACING
2930 mod->trace_events = section_objs(info, "_ftrace_events",
2931 sizeof(*mod->trace_events),
2932 &mod->num_trace_events);
2933 mod->trace_enums = section_objs(info, "_ftrace_enum_map",
2934 sizeof(*mod->trace_enums),
2935 &mod->num_trace_enums);
2936 #endif
2937 #ifdef CONFIG_TRACING
2938 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2939 sizeof(*mod->trace_bprintk_fmt_start),
2940 &mod->num_trace_bprintk_fmt);
2941 #endif
2942 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
2943 /* sechdrs[0].sh_size is always zero */
2944 mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2945 sizeof(*mod->ftrace_callsites),
2946 &mod->num_ftrace_callsites);
2947 #endif
2948
2949 mod->extable = section_objs(info, "__ex_table",
2950 sizeof(*mod->extable), &mod->num_exentries);
2951
2952 if (section_addr(info, "__obsparm"))
2953 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
2954
2955 info->debug = section_objs(info, "__verbose",
2956 sizeof(*info->debug), &info->num_debug);
2957
2958 return 0;
2959 }
2960
2961 static int move_module(struct module *mod, struct load_info *info)
2962 {
2963 int i;
2964 void *ptr;
2965
2966 /* Do the allocs. */
2967 ptr = module_alloc(mod->core_size);
2968 /*
2969 * The pointer to this block is stored in the module structure
2970 * which is inside the block. Just mark it as not being a
2971 * leak.
2972 */
2973 kmemleak_not_leak(ptr);
2974 if (!ptr)
2975 return -ENOMEM;
2976
2977 memset(ptr, 0, mod->core_size);
2978 mod->module_core = ptr;
2979
2980 if (mod->init_size) {
2981 ptr = module_alloc(mod->init_size);
2982 /*
2983 * The pointer to this block is stored in the module structure
2984 * which is inside the block. This block doesn't need to be
2985 * scanned as it contains data and code that will be freed
2986 * after the module is initialized.
2987 */
2988 kmemleak_ignore(ptr);
2989 if (!ptr) {
2990 module_memfree(mod->module_core);
2991 return -ENOMEM;
2992 }
2993 memset(ptr, 0, mod->init_size);
2994 mod->module_init = ptr;
2995 } else
2996 mod->module_init = NULL;
2997
2998 /* Transfer each section which specifies SHF_ALLOC */
2999 pr_debug("final section addresses:\n");
3000 for (i = 0; i < info->hdr->e_shnum; i++) {
3001 void *dest;
3002 Elf_Shdr *shdr = &info->sechdrs[i];
3003
3004 if (!(shdr->sh_flags & SHF_ALLOC))
3005 continue;
3006
3007 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3008 dest = mod->module_init
3009 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3010 else
3011 dest = mod->module_core + shdr->sh_entsize;
3012
3013 if (shdr->sh_type != SHT_NOBITS)
3014 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3015 /* Update sh_addr to point to copy in image. */
3016 shdr->sh_addr = (unsigned long)dest;
3017 pr_debug("\t0x%lx %s\n",
3018 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3019 }
3020
3021 return 0;
3022 }
3023
3024 static int check_module_license_and_versions(struct module *mod)
3025 {
3026 /*
3027 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3028 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3029 * using GPL-only symbols it needs.
3030 */
3031 if (strcmp(mod->name, "ndiswrapper") == 0)
3032 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3033
3034 /* driverloader was caught wrongly pretending to be under GPL */
3035 if (strcmp(mod->name, "driverloader") == 0)
3036 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3037 LOCKDEP_NOW_UNRELIABLE);
3038
3039 /* lve claims to be GPL but upstream won't provide source */
3040 if (strcmp(mod->name, "lve") == 0)
3041 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3042 LOCKDEP_NOW_UNRELIABLE);
3043
3044 #ifdef CONFIG_MODVERSIONS
3045 if ((mod->num_syms && !mod->crcs)
3046 || (mod->num_gpl_syms && !mod->gpl_crcs)
3047 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3048 #ifdef CONFIG_UNUSED_SYMBOLS
3049 || (mod->num_unused_syms && !mod->unused_crcs)
3050 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3051 #endif
3052 ) {
3053 return try_to_force_load(mod,
3054 "no versions for exported symbols");
3055 }
3056 #endif
3057 return 0;
3058 }
3059
3060 static void flush_module_icache(const struct module *mod)
3061 {
3062 mm_segment_t old_fs;
3063
3064 /* flush the icache in correct context */
3065 old_fs = get_fs();
3066 set_fs(KERNEL_DS);
3067
3068 /*
3069 * Flush the instruction cache, since we've played with text.
3070 * Do it before processing of module parameters, so the module
3071 * can provide parameter accessor functions of its own.
3072 */
3073 if (mod->module_init)
3074 flush_icache_range((unsigned long)mod->module_init,
3075 (unsigned long)mod->module_init
3076 + mod->init_size);
3077 flush_icache_range((unsigned long)mod->module_core,
3078 (unsigned long)mod->module_core + mod->core_size);
3079
3080 set_fs(old_fs);
3081 }
3082
3083 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3084 Elf_Shdr *sechdrs,
3085 char *secstrings,
3086 struct module *mod)
3087 {
3088 return 0;
3089 }
3090
3091 static struct module *layout_and_allocate(struct load_info *info, int flags)
3092 {
3093 /* Module within temporary copy. */
3094 struct module *mod;
3095 int err;
3096
3097 mod = setup_load_info(info, flags);
3098 if (IS_ERR(mod))
3099 return mod;
3100
3101 err = check_modinfo(mod, info, flags);
3102 if (err)
3103 return ERR_PTR(err);
3104
3105 /* Allow arches to frob section contents and sizes. */
3106 err = module_frob_arch_sections(info->hdr, info->sechdrs,
3107 info->secstrings, mod);
3108 if (err < 0)
3109 return ERR_PTR(err);
3110
3111 /* We will do a special allocation for per-cpu sections later. */
3112 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3113
3114 /* Determine total sizes, and put offsets in sh_entsize. For now
3115 this is done generically; there doesn't appear to be any
3116 special cases for the architectures. */
3117 layout_sections(mod, info);
3118 layout_symtab(mod, info);
3119
3120 /* Allocate and move to the final place */
3121 err = move_module(mod, info);
3122 if (err)
3123 return ERR_PTR(err);
3124
3125 /* Module has been copied to its final place now: return it. */
3126 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3127 kmemleak_load_module(mod, info);
3128 return mod;
3129 }
3130
3131 /* mod is no longer valid after this! */
3132 static void module_deallocate(struct module *mod, struct load_info *info)
3133 {
3134 percpu_modfree(mod);
3135 module_arch_freeing_init(mod);
3136 module_memfree(mod->module_init);
3137 module_memfree(mod->module_core);
3138 }
3139
3140 int __weak module_finalize(const Elf_Ehdr *hdr,
3141 const Elf_Shdr *sechdrs,
3142 struct module *me)
3143 {
3144 return 0;
3145 }
3146
3147 static int post_relocation(struct module *mod, const struct load_info *info)
3148 {
3149 /* Sort exception table now relocations are done. */
3150 sort_extable(mod->extable, mod->extable + mod->num_exentries);
3151
3152 /* Copy relocated percpu area over. */
3153 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3154 info->sechdrs[info->index.pcpu].sh_size);
3155
3156 /* Setup kallsyms-specific fields. */
3157 add_kallsyms(mod, info);
3158
3159 /* Arch-specific module finalizing. */
3160 return module_finalize(info->hdr, info->sechdrs, mod);
3161 }
3162
3163 /* Is this module of this name done loading? No locks held. */
3164 static bool finished_loading(const char *name)
3165 {
3166 struct module *mod;
3167 bool ret;
3168
3169 /*
3170 * The module_mutex should not be a heavily contended lock;
3171 * if we get the occasional sleep here, we'll go an extra iteration
3172 * in the wait_event_interruptible(), which is harmless.
3173 */
3174 sched_annotate_sleep();
3175 mutex_lock(&module_mutex);
3176 mod = find_module_all(name, strlen(name), true);
3177 ret = !mod || mod->state == MODULE_STATE_LIVE
3178 || mod->state == MODULE_STATE_GOING;
3179 mutex_unlock(&module_mutex);
3180
3181 return ret;
3182 }
3183
3184 /* Call module constructors. */
3185 static void do_mod_ctors(struct module *mod)
3186 {
3187 #ifdef CONFIG_CONSTRUCTORS
3188 unsigned long i;
3189
3190 for (i = 0; i < mod->num_ctors; i++)
3191 mod->ctors[i]();
3192 #endif
3193 }
3194
3195 /* For freeing module_init on success, in case kallsyms traversing */
3196 struct mod_initfree {
3197 struct rcu_head rcu;
3198 void *module_init;
3199 };
3200
3201 static void do_free_init(struct rcu_head *head)
3202 {
3203 struct mod_initfree *m = container_of(head, struct mod_initfree, rcu);
3204 module_memfree(m->module_init);
3205 kfree(m);
3206 }
3207
3208 /*
3209 * This is where the real work happens.
3210 *
3211 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3212 * helper command 'lx-symbols'.
3213 */
3214 static noinline int do_init_module(struct module *mod)
3215 {
3216 int ret = 0;
3217 struct mod_initfree *freeinit;
3218
3219 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3220 if (!freeinit) {
3221 ret = -ENOMEM;
3222 goto fail;
3223 }
3224 freeinit->module_init = mod->module_init;
3225
3226 /*
3227 * We want to find out whether @mod uses async during init. Clear
3228 * PF_USED_ASYNC. async_schedule*() will set it.
3229 */
3230 current->flags &= ~PF_USED_ASYNC;
3231
3232 do_mod_ctors(mod);
3233 /* Start the module */
3234 if (mod->init != NULL)
3235 ret = do_one_initcall(mod->init);
3236 if (ret < 0) {
3237 goto fail_free_freeinit;
3238 }
3239 if (ret > 0) {
3240 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3241 "follow 0/-E convention\n"
3242 "%s: loading module anyway...\n",
3243 __func__, mod->name, ret, __func__);
3244 dump_stack();
3245 }
3246
3247 /* Now it's a first class citizen! */
3248 mod->state = MODULE_STATE_LIVE;
3249 blocking_notifier_call_chain(&module_notify_list,
3250 MODULE_STATE_LIVE, mod);
3251
3252 /*
3253 * We need to finish all async code before the module init sequence
3254 * is done. This has potential to deadlock. For example, a newly
3255 * detected block device can trigger request_module() of the
3256 * default iosched from async probing task. Once userland helper
3257 * reaches here, async_synchronize_full() will wait on the async
3258 * task waiting on request_module() and deadlock.
3259 *
3260 * This deadlock is avoided by perfomring async_synchronize_full()
3261 * iff module init queued any async jobs. This isn't a full
3262 * solution as it will deadlock the same if module loading from
3263 * async jobs nests more than once; however, due to the various
3264 * constraints, this hack seems to be the best option for now.
3265 * Please refer to the following thread for details.
3266 *
3267 * http://thread.gmane.org/gmane.linux.kernel/1420814
3268 */
3269 if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3270 async_synchronize_full();
3271
3272 mutex_lock(&module_mutex);
3273 /* Drop initial reference. */
3274 module_put(mod);
3275 trim_init_extable(mod);
3276 #ifdef CONFIG_KALLSYMS
3277 mod->num_symtab = mod->core_num_syms;
3278 mod->symtab = mod->core_symtab;
3279 mod->strtab = mod->core_strtab;
3280 #endif
3281 mod_tree_remove_init(mod);
3282 unset_module_init_ro_nx(mod);
3283 module_arch_freeing_init(mod);
3284 mod->module_init = NULL;
3285 mod->init_size = 0;
3286 mod->init_ro_size = 0;
3287 mod->init_text_size = 0;
3288 /*
3289 * We want to free module_init, but be aware that kallsyms may be
3290 * walking this with preempt disabled. In all the failure paths, we
3291 * call synchronize_sched(), but we don't want to slow down the success
3292 * path, so use actual RCU here.
3293 */
3294 call_rcu_sched(&freeinit->rcu, do_free_init);
3295 mutex_unlock(&module_mutex);
3296 wake_up_all(&module_wq);
3297
3298 return 0;
3299
3300 fail_free_freeinit:
3301 kfree(freeinit);
3302 fail:
3303 /* Try to protect us from buggy refcounters. */
3304 mod->state = MODULE_STATE_GOING;
3305 synchronize_sched();
3306 module_put(mod);
3307 blocking_notifier_call_chain(&module_notify_list,
3308 MODULE_STATE_GOING, mod);
3309 free_module(mod);
3310 wake_up_all(&module_wq);
3311 return ret;
3312 }
3313
3314 static int may_init_module(void)
3315 {
3316 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3317 return -EPERM;
3318
3319 return 0;
3320 }
3321
3322 /*
3323 * We try to place it in the list now to make sure it's unique before
3324 * we dedicate too many resources. In particular, temporary percpu
3325 * memory exhaustion.
3326 */
3327 static int add_unformed_module(struct module *mod)
3328 {
3329 int err;
3330 struct module *old;
3331
3332 mod->state = MODULE_STATE_UNFORMED;
3333
3334 again:
3335 mutex_lock(&module_mutex);
3336 old = find_module_all(mod->name, strlen(mod->name), true);
3337 if (old != NULL) {
3338 if (old->state == MODULE_STATE_COMING
3339 || old->state == MODULE_STATE_UNFORMED) {
3340 /* Wait in case it fails to load. */
3341 mutex_unlock(&module_mutex);
3342 err = wait_event_interruptible(module_wq,
3343 finished_loading(mod->name));
3344 if (err)
3345 goto out_unlocked;
3346 goto again;
3347 }
3348 err = -EEXIST;
3349 goto out;
3350 }
3351 mod_update_bounds(mod);
3352 list_add_rcu(&mod->list, &modules);
3353 mod_tree_insert(mod);
3354 err = 0;
3355
3356 out:
3357 mutex_unlock(&module_mutex);
3358 out_unlocked:
3359 return err;
3360 }
3361
3362 static int complete_formation(struct module *mod, struct load_info *info)
3363 {
3364 int err;
3365
3366 mutex_lock(&module_mutex);
3367
3368 /* Find duplicate symbols (must be called under lock). */
3369 err = verify_export_symbols(mod);
3370 if (err < 0)
3371 goto out;
3372
3373 /* This relies on module_mutex for list integrity. */
3374 module_bug_finalize(info->hdr, info->sechdrs, mod);
3375
3376 /* Set RO and NX regions for core */
3377 set_section_ro_nx(mod->module_core,
3378 mod->core_text_size,
3379 mod->core_ro_size,
3380 mod->core_size);
3381
3382 /* Set RO and NX regions for init */
3383 set_section_ro_nx(mod->module_init,
3384 mod->init_text_size,
3385 mod->init_ro_size,
3386 mod->init_size);
3387
3388 /* Mark state as coming so strong_try_module_get() ignores us,
3389 * but kallsyms etc. can see us. */
3390 mod->state = MODULE_STATE_COMING;
3391 mutex_unlock(&module_mutex);
3392
3393 blocking_notifier_call_chain(&module_notify_list,
3394 MODULE_STATE_COMING, mod);
3395 return 0;
3396
3397 out:
3398 mutex_unlock(&module_mutex);
3399 return err;
3400 }
3401
3402 static int unknown_module_param_cb(char *param, char *val, const char *modname,
3403 void *arg)
3404 {
3405 struct module *mod = arg;
3406 int ret;
3407
3408 if (strcmp(param, "async_probe") == 0) {
3409 mod->async_probe_requested = true;
3410 return 0;
3411 }
3412
3413 /* Check for magic 'dyndbg' arg */
3414 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3415 if (ret != 0)
3416 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3417 return 0;
3418 }
3419
3420 /* Allocate and load the module: note that size of section 0 is always
3421 zero, and we rely on this for optional sections. */
3422 static int load_module(struct load_info *info, const char __user *uargs,
3423 int flags)
3424 {
3425 struct module *mod;
3426 long err;
3427 char *after_dashes;
3428
3429 err = module_sig_check(info);
3430 if (err)
3431 goto free_copy;
3432
3433 err = elf_header_check(info);
3434 if (err)
3435 goto free_copy;
3436
3437 /* Figure out module layout, and allocate all the memory. */
3438 mod = layout_and_allocate(info, flags);
3439 if (IS_ERR(mod)) {
3440 err = PTR_ERR(mod);
3441 goto free_copy;
3442 }
3443
3444 /* Reserve our place in the list. */
3445 err = add_unformed_module(mod);
3446 if (err)
3447 goto free_module;
3448
3449 #ifdef CONFIG_MODULE_SIG
3450 mod->sig_ok = info->sig_ok;
3451 if (!mod->sig_ok) {
3452 pr_notice_once("%s: module verification failed: signature "
3453 "and/or required key missing - tainting "
3454 "kernel\n", mod->name);
3455 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3456 }
3457 #endif
3458
3459 /* To avoid stressing percpu allocator, do this once we're unique. */
3460 err = percpu_modalloc(mod, info);
3461 if (err)
3462 goto unlink_mod;
3463
3464 /* Now module is in final location, initialize linked lists, etc. */
3465 err = module_unload_init(mod);
3466 if (err)
3467 goto unlink_mod;
3468
3469 init_param_lock(mod);
3470
3471 /* Now we've got everything in the final locations, we can
3472 * find optional sections. */
3473 err = find_module_sections(mod, info);
3474 if (err)
3475 goto free_unload;
3476
3477 err = check_module_license_and_versions(mod);
3478 if (err)
3479 goto free_unload;
3480
3481 /* Set up MODINFO_ATTR fields */
3482 setup_modinfo(mod, info);
3483
3484 /* Fix up syms, so that st_value is a pointer to location. */
3485 err = simplify_symbols(mod, info);
3486 if (err < 0)
3487 goto free_modinfo;
3488
3489 err = apply_relocations(mod, info);
3490 if (err < 0)
3491 goto free_modinfo;
3492
3493 err = post_relocation(mod, info);
3494 if (err < 0)
3495 goto free_modinfo;
3496
3497 flush_module_icache(mod);
3498
3499 /* Now copy in args */
3500 mod->args = strndup_user(uargs, ~0UL >> 1);
3501 if (IS_ERR(mod->args)) {
3502 err = PTR_ERR(mod->args);
3503 goto free_arch_cleanup;
3504 }
3505
3506 dynamic_debug_setup(info->debug, info->num_debug);
3507
3508 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3509 ftrace_module_init(mod);
3510
3511 /* Finally it's fully formed, ready to start executing. */
3512 err = complete_formation(mod, info);
3513 if (err)
3514 goto ddebug_cleanup;
3515
3516 /* Module is ready to execute: parsing args may do that. */
3517 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3518 -32768, 32767, NULL,
3519 unknown_module_param_cb);
3520 if (IS_ERR(after_dashes)) {
3521 err = PTR_ERR(after_dashes);
3522 goto bug_cleanup;
3523 } else if (after_dashes) {
3524 pr_warn("%s: parameters '%s' after `--' ignored\n",
3525 mod->name, after_dashes);
3526 }
3527
3528 /* Link in to syfs. */
3529 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3530 if (err < 0)
3531 goto bug_cleanup;
3532
3533 /* Get rid of temporary copy. */
3534 free_copy(info);
3535
3536 /* Done! */
3537 trace_module_load(mod);
3538
3539 return do_init_module(mod);
3540
3541 bug_cleanup:
3542 /* module_bug_cleanup needs module_mutex protection */
3543 mutex_lock(&module_mutex);
3544 module_bug_cleanup(mod);
3545 mutex_unlock(&module_mutex);
3546
3547 blocking_notifier_call_chain(&module_notify_list,
3548 MODULE_STATE_GOING, mod);
3549
3550 /* we can't deallocate the module until we clear memory protection */
3551 unset_module_init_ro_nx(mod);
3552 unset_module_core_ro_nx(mod);
3553
3554 ddebug_cleanup:
3555 dynamic_debug_remove(info->debug);
3556 synchronize_sched();
3557 kfree(mod->args);
3558 free_arch_cleanup:
3559 module_arch_cleanup(mod);
3560 free_modinfo:
3561 free_modinfo(mod);
3562 free_unload:
3563 module_unload_free(mod);
3564 unlink_mod:
3565 mutex_lock(&module_mutex);
3566 /* Unlink carefully: kallsyms could be walking list. */
3567 list_del_rcu(&mod->list);
3568 mod_tree_remove(mod);
3569 wake_up_all(&module_wq);
3570 /* Wait for RCU-sched synchronizing before releasing mod->list. */
3571 synchronize_sched();
3572 mutex_unlock(&module_mutex);
3573 free_module:
3574 /* Free lock-classes; relies on the preceding sync_rcu() */
3575 lockdep_free_key_range(mod->module_core, mod->core_size);
3576
3577 module_deallocate(mod, info);
3578 free_copy:
3579 free_copy(info);
3580 return err;
3581 }
3582
3583 SYSCALL_DEFINE3(init_module, void __user *, umod,
3584 unsigned long, len, const char __user *, uargs)
3585 {
3586 int err;
3587 struct load_info info = { };
3588
3589 err = may_init_module();
3590 if (err)
3591 return err;
3592
3593 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3594 umod, len, uargs);
3595
3596 err = copy_module_from_user(umod, len, &info);
3597 if (err)
3598 return err;
3599
3600 return load_module(&info, uargs, 0);
3601 }
3602
3603 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3604 {
3605 int err;
3606 struct load_info info = { };
3607
3608 err = may_init_module();
3609 if (err)
3610 return err;
3611
3612 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3613
3614 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3615 |MODULE_INIT_IGNORE_VERMAGIC))
3616 return -EINVAL;
3617
3618 err = copy_module_from_fd(fd, &info);
3619 if (err)
3620 return err;
3621
3622 return load_module(&info, uargs, flags);
3623 }
3624
3625 static inline int within(unsigned long addr, void *start, unsigned long size)
3626 {
3627 return ((void *)addr >= start && (void *)addr < start + size);
3628 }
3629
3630 #ifdef CONFIG_KALLSYMS
3631 /*
3632 * This ignores the intensely annoying "mapping symbols" found
3633 * in ARM ELF files: $a, $t and $d.
3634 */
3635 static inline int is_arm_mapping_symbol(const char *str)
3636 {
3637 if (str[0] == '.' && str[1] == 'L')
3638 return true;
3639 return str[0] == '$' && strchr("axtd", str[1])
3640 && (str[2] == '\0' || str[2] == '.');
3641 }
3642
3643 static const char *get_ksymbol(struct module *mod,
3644 unsigned long addr,
3645 unsigned long *size,
3646 unsigned long *offset)
3647 {
3648 unsigned int i, best = 0;
3649 unsigned long nextval;
3650
3651 /* At worse, next value is at end of module */
3652 if (within_module_init(addr, mod))
3653 nextval = (unsigned long)mod->module_init+mod->init_text_size;
3654 else
3655 nextval = (unsigned long)mod->module_core+mod->core_text_size;
3656
3657 /* Scan for closest preceding symbol, and next symbol. (ELF
3658 starts real symbols at 1). */
3659 for (i = 1; i < mod->num_symtab; i++) {
3660 if (mod->symtab[i].st_shndx == SHN_UNDEF)
3661 continue;
3662
3663 /* We ignore unnamed symbols: they're uninformative
3664 * and inserted at a whim. */
3665 if (mod->symtab[i].st_value <= addr
3666 && mod->symtab[i].st_value > mod->symtab[best].st_value
3667 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3668 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3669 best = i;
3670 if (mod->symtab[i].st_value > addr
3671 && mod->symtab[i].st_value < nextval
3672 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3673 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3674 nextval = mod->symtab[i].st_value;
3675 }
3676
3677 if (!best)
3678 return NULL;
3679
3680 if (size)
3681 *size = nextval - mod->symtab[best].st_value;
3682 if (offset)
3683 *offset = addr - mod->symtab[best].st_value;
3684 return mod->strtab + mod->symtab[best].st_name;
3685 }
3686
3687 /* For kallsyms to ask for address resolution. NULL means not found. Careful
3688 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3689 const char *module_address_lookup(unsigned long addr,
3690 unsigned long *size,
3691 unsigned long *offset,
3692 char **modname,
3693 char *namebuf)
3694 {
3695 const char *ret = NULL;
3696 struct module *mod;
3697
3698 preempt_disable();
3699 mod = __module_address(addr);
3700 if (mod) {
3701 if (modname)
3702 *modname = mod->name;
3703 ret = get_ksymbol(mod, addr, size, offset);
3704 }
3705 /* Make a copy in here where it's safe */
3706 if (ret) {
3707 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3708 ret = namebuf;
3709 }
3710 preempt_enable();
3711
3712 return ret;
3713 }
3714
3715 int lookup_module_symbol_name(unsigned long addr, char *symname)
3716 {
3717 struct module *mod;
3718
3719 preempt_disable();
3720 list_for_each_entry_rcu(mod, &modules, list) {
3721 if (mod->state == MODULE_STATE_UNFORMED)
3722 continue;
3723 if (within_module(addr, mod)) {
3724 const char *sym;
3725
3726 sym = get_ksymbol(mod, addr, NULL, NULL);
3727 if (!sym)
3728 goto out;
3729 strlcpy(symname, sym, KSYM_NAME_LEN);
3730 preempt_enable();
3731 return 0;
3732 }
3733 }
3734 out:
3735 preempt_enable();
3736 return -ERANGE;
3737 }
3738
3739 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3740 unsigned long *offset, char *modname, char *name)
3741 {
3742 struct module *mod;
3743
3744 preempt_disable();
3745 list_for_each_entry_rcu(mod, &modules, list) {
3746 if (mod->state == MODULE_STATE_UNFORMED)
3747 continue;
3748 if (within_module(addr, mod)) {
3749 const char *sym;
3750
3751 sym = get_ksymbol(mod, addr, size, offset);
3752 if (!sym)
3753 goto out;
3754 if (modname)
3755 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3756 if (name)
3757 strlcpy(name, sym, KSYM_NAME_LEN);
3758 preempt_enable();
3759 return 0;
3760 }
3761 }
3762 out:
3763 preempt_enable();
3764 return -ERANGE;
3765 }
3766
3767 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3768 char *name, char *module_name, int *exported)
3769 {
3770 struct module *mod;
3771
3772 preempt_disable();
3773 list_for_each_entry_rcu(mod, &modules, list) {
3774 if (mod->state == MODULE_STATE_UNFORMED)
3775 continue;
3776 if (symnum < mod->num_symtab) {
3777 *value = mod->symtab[symnum].st_value;
3778 *type = mod->symtab[symnum].st_info;
3779 strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3780 KSYM_NAME_LEN);
3781 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3782 *exported = is_exported(name, *value, mod);
3783 preempt_enable();
3784 return 0;
3785 }
3786 symnum -= mod->num_symtab;
3787 }
3788 preempt_enable();
3789 return -ERANGE;
3790 }
3791
3792 static unsigned long mod_find_symname(struct module *mod, const char *name)
3793 {
3794 unsigned int i;
3795
3796 for (i = 0; i < mod->num_symtab; i++)
3797 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
3798 mod->symtab[i].st_info != 'U')
3799 return mod->symtab[i].st_value;
3800 return 0;
3801 }
3802
3803 /* Look for this name: can be of form module:name. */
3804 unsigned long module_kallsyms_lookup_name(const char *name)
3805 {
3806 struct module *mod;
3807 char *colon;
3808 unsigned long ret = 0;
3809
3810 /* Don't lock: we're in enough trouble already. */
3811 preempt_disable();
3812 if ((colon = strchr(name, ':')) != NULL) {
3813 if ((mod = find_module_all(name, colon - name, false)) != NULL)
3814 ret = mod_find_symname(mod, colon+1);
3815 } else {
3816 list_for_each_entry_rcu(mod, &modules, list) {
3817 if (mod->state == MODULE_STATE_UNFORMED)
3818 continue;
3819 if ((ret = mod_find_symname(mod, name)) != 0)
3820 break;
3821 }
3822 }
3823 preempt_enable();
3824 return ret;
3825 }
3826
3827 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
3828 struct module *, unsigned long),
3829 void *data)
3830 {
3831 struct module *mod;
3832 unsigned int i;
3833 int ret;
3834
3835 module_assert_mutex();
3836
3837 list_for_each_entry(mod, &modules, list) {
3838 if (mod->state == MODULE_STATE_UNFORMED)
3839 continue;
3840 for (i = 0; i < mod->num_symtab; i++) {
3841 ret = fn(data, mod->strtab + mod->symtab[i].st_name,
3842 mod, mod->symtab[i].st_value);
3843 if (ret != 0)
3844 return ret;
3845 }
3846 }
3847 return 0;
3848 }
3849 #endif /* CONFIG_KALLSYMS */
3850
3851 static char *module_flags(struct module *mod, char *buf)
3852 {
3853 int bx = 0;
3854
3855 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3856 if (mod->taints ||
3857 mod->state == MODULE_STATE_GOING ||
3858 mod->state == MODULE_STATE_COMING) {
3859 buf[bx++] = '(';
3860 bx += module_flags_taint(mod, buf + bx);
3861 /* Show a - for module-is-being-unloaded */
3862 if (mod->state == MODULE_STATE_GOING)
3863 buf[bx++] = '-';
3864 /* Show a + for module-is-being-loaded */
3865 if (mod->state == MODULE_STATE_COMING)
3866 buf[bx++] = '+';
3867 buf[bx++] = ')';
3868 }
3869 buf[bx] = '\0';
3870
3871 return buf;
3872 }
3873
3874 #ifdef CONFIG_PROC_FS
3875 /* Called by the /proc file system to return a list of modules. */
3876 static void *m_start(struct seq_file *m, loff_t *pos)
3877 {
3878 mutex_lock(&module_mutex);
3879 return seq_list_start(&modules, *pos);
3880 }
3881
3882 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
3883 {
3884 return seq_list_next(p, &modules, pos);
3885 }
3886
3887 static void m_stop(struct seq_file *m, void *p)
3888 {
3889 mutex_unlock(&module_mutex);
3890 }
3891
3892 static int m_show(struct seq_file *m, void *p)
3893 {
3894 struct module *mod = list_entry(p, struct module, list);
3895 char buf[8];
3896
3897 /* We always ignore unformed modules. */
3898 if (mod->state == MODULE_STATE_UNFORMED)
3899 return 0;
3900
3901 seq_printf(m, "%s %u",
3902 mod->name, mod->init_size + mod->core_size);
3903 print_unload_info(m, mod);
3904
3905 /* Informative for users. */
3906 seq_printf(m, " %s",
3907 mod->state == MODULE_STATE_GOING ? "Unloading" :
3908 mod->state == MODULE_STATE_COMING ? "Loading" :
3909 "Live");
3910 /* Used by oprofile and other similar tools. */
3911 seq_printf(m, " 0x%pK", mod->module_core);
3912
3913 /* Taints info */
3914 if (mod->taints)
3915 seq_printf(m, " %s", module_flags(mod, buf));
3916
3917 seq_puts(m, "\n");
3918 return 0;
3919 }
3920
3921 /* Format: modulename size refcount deps address
3922
3923 Where refcount is a number or -, and deps is a comma-separated list
3924 of depends or -.
3925 */
3926 static const struct seq_operations modules_op = {
3927 .start = m_start,
3928 .next = m_next,
3929 .stop = m_stop,
3930 .show = m_show
3931 };
3932
3933 static int modules_open(struct inode *inode, struct file *file)
3934 {
3935 return seq_open(file, &modules_op);
3936 }
3937
3938 static const struct file_operations proc_modules_operations = {
3939 .open = modules_open,
3940 .read = seq_read,
3941 .llseek = seq_lseek,
3942 .release = seq_release,
3943 };
3944
3945 static int __init proc_modules_init(void)
3946 {
3947 proc_create("modules", 0, NULL, &proc_modules_operations);
3948 return 0;
3949 }
3950 module_init(proc_modules_init);
3951 #endif
3952
3953 /* Given an address, look for it in the module exception tables. */
3954 const struct exception_table_entry *search_module_extables(unsigned long addr)
3955 {
3956 const struct exception_table_entry *e = NULL;
3957 struct module *mod;
3958
3959 preempt_disable();
3960 list_for_each_entry_rcu(mod, &modules, list) {
3961 if (mod->state == MODULE_STATE_UNFORMED)
3962 continue;
3963 if (mod->num_exentries == 0)
3964 continue;
3965
3966 e = search_extable(mod->extable,
3967 mod->extable + mod->num_exentries - 1,
3968 addr);
3969 if (e)
3970 break;
3971 }
3972 preempt_enable();
3973
3974 /* Now, if we found one, we are running inside it now, hence
3975 we cannot unload the module, hence no refcnt needed. */
3976 return e;
3977 }
3978
3979 /*
3980 * is_module_address - is this address inside a module?
3981 * @addr: the address to check.
3982 *
3983 * See is_module_text_address() if you simply want to see if the address
3984 * is code (not data).
3985 */
3986 bool is_module_address(unsigned long addr)
3987 {
3988 bool ret;
3989
3990 preempt_disable();
3991 ret = __module_address(addr) != NULL;
3992 preempt_enable();
3993
3994 return ret;
3995 }
3996
3997 /*
3998 * __module_address - get the module which contains an address.
3999 * @addr: the address.
4000 *
4001 * Must be called with preempt disabled or module mutex held so that
4002 * module doesn't get freed during this.
4003 */
4004 struct module *__module_address(unsigned long addr)
4005 {
4006 struct module *mod;
4007
4008 if (addr < module_addr_min || addr > module_addr_max)
4009 return NULL;
4010
4011 module_assert_mutex_or_preempt();
4012
4013 mod = mod_find(addr);
4014 if (mod) {
4015 BUG_ON(!within_module(addr, mod));
4016 if (mod->state == MODULE_STATE_UNFORMED)
4017 mod = NULL;
4018 }
4019 return mod;
4020 }
4021 EXPORT_SYMBOL_GPL(__module_address);
4022
4023 /*
4024 * is_module_text_address - is this address inside module code?
4025 * @addr: the address to check.
4026 *
4027 * See is_module_address() if you simply want to see if the address is
4028 * anywhere in a module. See kernel_text_address() for testing if an
4029 * address corresponds to kernel or module code.
4030 */
4031 bool is_module_text_address(unsigned long addr)
4032 {
4033 bool ret;
4034
4035 preempt_disable();
4036 ret = __module_text_address(addr) != NULL;
4037 preempt_enable();
4038
4039 return ret;
4040 }
4041
4042 /*
4043 * __module_text_address - get the module whose code contains an address.
4044 * @addr: the address.
4045 *
4046 * Must be called with preempt disabled or module mutex held so that
4047 * module doesn't get freed during this.
4048 */
4049 struct module *__module_text_address(unsigned long addr)
4050 {
4051 struct module *mod = __module_address(addr);
4052 if (mod) {
4053 /* Make sure it's within the text section. */
4054 if (!within(addr, mod->module_init, mod->init_text_size)
4055 && !within(addr, mod->module_core, mod->core_text_size))
4056 mod = NULL;
4057 }
4058 return mod;
4059 }
4060 EXPORT_SYMBOL_GPL(__module_text_address);
4061
4062 /* Don't grab lock, we're oopsing. */
4063 void print_modules(void)
4064 {
4065 struct module *mod;
4066 char buf[8];
4067
4068 printk(KERN_DEFAULT "Modules linked in:");
4069 /* Most callers should already have preempt disabled, but make sure */
4070 preempt_disable();
4071 list_for_each_entry_rcu(mod, &modules, list) {
4072 if (mod->state == MODULE_STATE_UNFORMED)
4073 continue;
4074 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4075 }
4076 preempt_enable();
4077 if (last_unloaded_module[0])
4078 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4079 pr_cont("\n");
4080 }
4081
4082 #ifdef CONFIG_MODVERSIONS
4083 /* Generate the signature for all relevant module structures here.
4084 * If these change, we don't want to try to parse the module. */
4085 void module_layout(struct module *mod,
4086 struct modversion_info *ver,
4087 struct kernel_param *kp,
4088 struct kernel_symbol *ks,
4089 struct tracepoint * const *tp)
4090 {
4091 }
4092 EXPORT_SYMBOL(module_layout);
4093 #endif